diff --git a/data/prefs.lkshp b/data/prefs.lkshp
--- a/data/prefs.lkshp
+++ b/data/prefs.lkshp
@@ -46,7 +46,7 @@
 Paths under which haskell sources for packages may be found:
                []
 Unpack source for cabal packages to:
-               Just "~/.leksah-0.13/packageSources"
+               Just "~/.leksah-0.14/packageSources"
 URL from which to download prebuilt metadata:
                "http://www.leksah.org"
 Strategy for downloading prebuilt metadata:
diff --git a/data/prefscoll.lkshp b/data/prefscoll.lkshp
--- a/data/prefscoll.lkshp
+++ b/data/prefscoll.lkshp
@@ -1,7 +1,7 @@
 Paths under which haskell sources for packages may be found:
                []
 Unpack source for cabal packages to:
-               Just "~/.leksah-0.13/packageSources"
+               Just "~/.leksah-0.14/packageSources"
 URL from which to download prebuilt metadata:
                "http://www.leksah.org"
 Strategy for downloading prebuilt metadata:
diff --git a/leksah.cabal b/leksah.cabal
--- a/leksah.cabal
+++ b/leksah.cabal
@@ -1,5 +1,5 @@
 name: leksah
-version: 0.13.4.3
+version: 0.14.0.0
 cabal-version: >=1.10
 build-type: Simple
 license: GPL
@@ -207,12 +207,12 @@
 
     if os(osx)
         if flag(gtk3)
-          build-depends: gtk3-mac-integration >= 0.2.0.0 && <0.3
+          build-depends: gtk3-mac-integration >= 0.3.0.0 && <0.4
         else
-          build-depends: gtk-mac-integration >= 0.2.0.0 && <0.3
+          build-depends: gtk-mac-integration >= 0.3.0.0 && <0.4
 
     if flag(yi)
-        build-depends: yi >=0.8.1 && <0.9
+        build-depends: yi >=0.8.1 && <0.10
         cpp-options: -DLEKSAH_WITH_YI
 
     if flag(yi) && flag(dyre)
@@ -223,10 +223,10 @@
         ghc-options: -threaded
 
     if flag(gtk3)
-      build-depends: gtk3 >=0.12.4 && <0.13, gtksourceview3 >=0.10.0 && <0.13
+      build-depends: gtk3 >=0.13.0.0 && <0.14, gtksourceview3 >=0.13.0.0 && <0.14
       cpp-options:   -DMIN_VERSION_gtk=MIN_VERSION_gtk3
     else
-      build-depends: gtk >=0.12.4 && <0.13, gtksourceview2 >=0.10.0 && <0.13
+      build-depends: gtk >=0.13.0.0 && <0.14, gtksourceview2 >=0.13.0.0 && <0.14
 
     if flag(webkit)
         if flag(gtk3)
@@ -246,18 +246,18 @@
 
     build-depends: Cabal >=1.10.2.0 && <1.22, base >=4.0.0.0 && <4.8, binary >=0.5.0.0 && <0.8,
                        bytestring >=0.9.0.1 && <0.11, containers >=0.2.0.0 && <0.6, directory >=1.0.0.2 && <3.1,
-                       filepath >=1.1.0.1 && <1.4, glib >=0.10 && <0.13,
-                       mtl >=1.1.0.2 && <2.2, old-time >=1.0.0.1 && <1.2,
+                       filepath >=1.1.0.1 && <1.4, glib >=0.13.0.0 && <0.14,
+                       mtl >=1.1.0.2 && <2.3, old-time >=1.0.0.1 && <1.2,
                        parsec >=2.1.0.1 && <3.2, pretty >=1.0.1.0 && <1.2,
-                       regex-tdfa >=1.1 && <1.3, regex-base ==0.93.*, utf8-string >=0.3.1.1 && <0.4, array >=0.2.0.0 && <0.6,
-                       time >=0.1 && <1.5, ltk >= 0.13.2.0 && <0.14, binary-shared >= 0.8 && <0.9, deepseq >= 1.1.0.0 && <1.4,
-                       hslogger >= 1.0.7 && <1.3, leksah-server >=0.13.1.0 && <0.14, network >= 2.2 && <3.0,
-                       ghc >=6.10.1 && <7.9, strict >= 0.3.2 && <0.4, conduit >= 1.0.8 && <1.1, text >= 0.11.1.5 && < 1.2,
-                       gio >=0.12.2 && <0.13, transformers >=0.2.2.0 && <0.4,
+                       regex-tdfa >=1.1 && <1.3, regex-tdfa-text, regex-base ==0.93.*, utf8-string >=0.3.1.1 && <0.4, array >=0.2.0.0 && <0.6,
+                       time >=0.1 && <1.5, ltk >= 0.14.0.0 && <0.15, binary-shared >= 0.8 && <0.9, deepseq >= 1.1.0.0 && <1.4,
+                       hslogger >= 1.0.7 && <1.3, leksah-server >=0.14.0.0 && <0.15, network >= 2.2 && <3.0,
+                       ghc >=6.10.1 && <7.9, strict >= 0.3.2 && <0.4, conduit >= 1.0.8 && <1.2, text >= 0.11.1.5 && < 1.2,
+                       gio >=0.13.0.0 && <0.14, transformers >=0.2.2.0 && <0.5,
                        executable-path >=0.0.3 && <0.1,
-                       vcsgui >=0.0.4 && < 0.1, vcswrapper >=0.0.4 && < 0.1,
-                       QuickCheck >=2.4.2 && <2.7, haskell-src-exts >=1.13.5 && <1.15,
-                       hlint >=1.8.59 && <1.9, vado >=0.0.1 && <0.1, shakespeare >=2.0.0.1 && <2.1
+                       vcsgui >=0.1.0 && < 0.2, vcswrapper >=0.1.0 && < 0.2,
+                       QuickCheck >=2.4.2 && <2.8, haskell-src-exts >=1.13.5 && <1.16,
+                       hlint >=1.8.59 && <1.10, vado >=0.0.1 && <0.1, shakespeare >=2.0.0.1 && <2.1
     exposed-modules: IDE.Leksah IDE.Completion IDE.ImportTool IDE.Find
                      IDE.Sandbox IDE.Session IDE.Command IDE.Keymap IDE.Utils.GUIUtils
                      IDE.SymbolNavigation IDE.Package IDE.YiConfig IDE.OSX
@@ -303,7 +303,7 @@
         ghc-options: -threaded
 
     hs-source-dirs: main
-    build-depends: leksah == 0.13.4.3, base >= 4.0.0.0 && <=4.8, gtk3 -any
+    build-depends: leksah == 0.14.0.0, base >= 4.0.0.0 && <=4.8, gtk3 -any
     if os(linux) && flag(loc)
         cpp-options: -DLOCALIZATION
         build-depends: hgettext, setlocale
@@ -322,14 +322,14 @@
     if !flag(webkit)
         buildable: False
     else
-        build-depends: leksah ==0.13.4.3, base >=4.0.0.0 && <=4.8,
+        build-depends: leksah ==0.14.0.0, base >=4.0.0.0 && <=4.8,
                        jsaddle -any, ghcjs-dom -any
         if flag(gtk3)
-          build-depends: gtk3 >=0.12.4 && <0.13, gtksourceview3 >=0.10.0 && <0.13,
+          build-depends: gtk3 >=0.13.0.0 && <0.14, gtksourceview3 >=0.13.0.0 && <0.14,
                          webkitgtk3 -any, webkitgtk3-javascriptcore -any
           cpp-options:   -DMIN_VERSION_gtk=MIN_VERSION_gtk3
         else
-          build-depends: gtk >=0.12.4 && <0.13, gtksourceview2 >=0.10.0 && <0.13,
+          build-depends: gtk >=0.13.0.0 && <0.14, gtksourceview2 >=0.13.0.0 && <0.14,
                          webkit -any, webkit-javascriptcore -any
 
     main-is: Main.hs
@@ -339,14 +339,14 @@
 
 test-suite tests
     build-depends: base >=4.0.0.0 && <4.8, Cabal >=1.10.2.0 && <1.22,
-                   QuickCheck >=2.4.2 && <2.7, leksah ==0.13.4.3,
+                   QuickCheck >=2.4.2 && <2.8, leksah ==0.14.0.0,
                    containers, ltk, leksah-server, hslogger,
                    transformers, glib, monad-loops
     if flag(gtk3)
-        build-depends: gtk3 >=0.12.4 && <0.13, gtksourceview3 >=0.10.0 && <0.13, webkitgtk3 -any
+        build-depends: gtk3 >=0.13.0.0 && <0.14, gtksourceview3 >=0.13.0.0 && <0.14, webkitgtk3 -any
         cpp-options:   -DMIN_VERSION_gtk=MIN_VERSION_gtk3
     else
-        build-depends: gtk >=0.12.4 && <0.13, gtksourceview2 >=0.10.0 && <0.13, webkit -any
+        build-depends: gtk >=0.13.0.0 && <0.14, gtksourceview2 >=0.13.0.0 && <0.14, webkit -any
     if flag(yi)
         build-depends: yi >=0.6.6.1 && <0.7
     type: exitcode-stdio-1.0
diff --git a/osx/Info.plist b/osx/Info.plist
--- a/osx/Info.plist
+++ b/osx/Info.plist
@@ -7,7 +7,7 @@
     <key>CFBundleExecutable</key>
     <string>Leksah</string>
     <key>CFBundleGetInfoString</key>
-    <string>0.13.0.0</string>
+    <string>0.14.0.0</string>
     <key>CFBundleIconFile</key>
     <string>leksah.icns</string>
     <key>CFBundleIdentifier</key>
@@ -17,11 +17,11 @@
     <key>CFBundlePackageType</key>
     <string>APPL</string>
     <key>CFBundleShortVersionString</key>
-    <string>0.13.0.0</string>
+    <string>0.14.0.0</string>
     <key>CFBundleSignature</key>
     <string>????</string>
     <key>CFBundleVersion</key>
-    <string>0.13.0.0</string>
+    <string>0.14.0.0</string>
     <key>NSHumanReadableCopyright</key>
     <string>2007-2011 Jürgen Nicklisch-Franken, GNU General Public License.</string>
     <key>LSMinimumSystemVersion</key>
diff --git a/osx/leksah.bundle b/osx/leksah.bundle
--- a/osx/leksah.bundle
+++ b/osx/leksah.bundle
@@ -13,8 +13,11 @@
          either define your own or just hardcode the path here.
     -->
     <prefix name="default">${env:JHBUILD_PREFIX}</prefix>
+    <prefix name="leksah-bin">${env:LEKSAH_BIN_DIR}</prefix>
     <prefix name="leksah">${env:LEKSAH_PREFIX}</prefix>
+    <prefix name="leksah-server-bin">${env:LEKSAH_SERVER_BIN_DIR}</prefix>
     <prefix name="leksah-server">${env:LEKSAH_SERVER_PREFIX}</prefix>
+    <prefix name="vcsgui-bin">${env:VCSGUI_BIN_DIR}</prefix>
     <prefix name="vcsgui">${env:VCSGUI_PREFIX}</prefix>
     <prefix name="hlint">${env:HLINT_PREFIX}</prefix>
 
@@ -54,12 +57,12 @@
   -->
   <plist>${project}/Info.plist</plist>
 
-  <main-binary>${prefix:leksah}/bin/leksah</main-binary>
+  <main-binary>${prefix:leksah-bin}/bin/leksah</main-binary>
 
-  <binary>${prefix:leksah-server}/bin/leksahecho</binary>
-  <binary>${prefix:leksah-server}/bin/leksah-server</binary>
-  <binary>${prefix:vcsgui}/bin/vcsgui</binary>
-  <binary>${prefix:vcsgui}/bin/vcsgui-askpass</binary>
+  <binary>${prefix:leksah-server-bin}/bin/leksahecho</binary>
+  <binary>${prefix:leksah-server-bin}/bin/leksah-server</binary>
+  <binary>${prefix:vcsgui-bin}/bin/vcsgui</binary>
+  <binary>${prefix:vcsgui-bin}/bin/vcsgui-askpass</binary>
 
   <!-- Copy in the input methods. Dunno if they actually work with
        OSX. Note the ${gtkdir} macro, which expands to the correct
@@ -132,11 +135,11 @@
   </data>
 
   <data dest="${bundle}/Contents/Resources/share/leksah">
-    ${prefix:leksah}/share
+    ${prefix:leksah}
   </data>
 
   <data dest="${bundle}/Contents/Resources/share/hlint">
-    ${prefix:hlint}/share
+    ${prefix:hlint}
   </data>
 
   <!-- Copy in the themes data. You may want to trim this to save space
diff --git a/osx/makedmg.sh b/osx/makedmg.sh
--- a/osx/makedmg.sh
+++ b/osx/makedmg.sh
@@ -5,11 +5,24 @@
 . scripts/stage.sh || exit
 
 export GHC_USER_PREFIX=$HOME/Library/Haskell/ghc-`ghc$GHCVERSION --numeric-version`/lib
-export LEKSAH_PREFIX=$GHC_USER_PREFIX/$LEKSAH_X_X_X_X
-export LEKSAH_SERVER_PREFIX=$GHC_USER_PREFIX/$LEKSAH_SERVER_X_X_X_X
-export VCSGUI_PREFIX=$GHC_USER_PREFIX/`ghc-pkg$GHCVERSION list |grep '^ *vcsgui-' | head -n1 | tr -d ' \n'`
+export LEKSAH_BIN_DIR=$GHC_USER_PREFIX/$LEKSAH_X_X_X_X
+export LEKSAH_PREFIX=$GHC_USER_PREFIX/$LEKSAH_X_X_X_X/share
+export LEKSAH_SERVER_BIN_DIR=$GHC_USER_PREFIX/$LEKSAH_SERVER_X_X_X_X
+export LEKSAH_SERVER_PREFIX=$GHC_USER_PREFIX/$LEKSAH_SERVER_X_X_X_X/share
+export VCSGUI_BIN_DIR=$GHC_USER_PREFIX/`ghc-pkg$GHCVERSION list |grep '^ *vcsgui-' | head -n1 | tr -d ' \n'`
+export VCSGUI_PREFIX=$GHC_USER_PREFIX/`ghc-pkg$GHCVERSION list |grep '^ *vcsgui-' | head -n1 | tr -d ' \n'`/share
 export HLINT_PREFIX=$GHC_USER_PREFIX/`ghc-pkg$GHCVERSION list |grep '^ *hlint-' | head -n1 | tr -d ' \n'`
 
+#export SANDBOX_BIN_DIR=$PWD/.cabal-sandbox
+#export SANDBOX_SHARE=$PWD/.cabal-sandbox/share/x86_64-osx-ghc-`ghc$GHCVERSION --numeric-version`
+#export LEKSAH_BIN_DIR=$SANDBOX_BIN_DIR
+#export LEKSAH_PREFIX=$SANDBOX_SHARE/$LEKSAH_X_X_X_X
+#export LEKSAH_SERVER_BIN_DIR=$SANDBOX_BIN_DIR
+#export LEKSAH_SERVER_PREFIX=$SANDBOX_SHARE/$LEKSAH_SERVER_X_X_X_X
+#export VCSGUI_BIN_DIR=$SANDBOX_BIN_DIR
+#export VCSGUI_PREFIX=$SANDBOX_SHARE/`ghc-pkg$GHCVERSION list |grep '^ *vcsgui-' | head -n1 | tr -d ' \n'`
+#export HLINT_PREFIX=$SANDBOX_SHARE/`ghc-pkg$GHCVERSION list |grep '^ *hlint-' | head -n1 | tr -d ' \n'`
+
 sed -e 's|TextView Font: *\"Monospace 10\"|TextView Font: "Monospace 14"|' -e 's|Browser: *\"firefox\"|Browser:       \"open\"|' <data/prefs.lkshp >osx/prefs.lkshp
 
 sed -e 's|\<ctrl\>|\<meta\>|' \
@@ -58,5 +71,5 @@
 if test -e "$LEKSAH_DMG"; then
    rm "$LEKSAH_DMG"
 fi
-hdiutil create -size 400m -srcfolder "Leksah" "$LEKSAH_DMG" || exit
+hdiutil create -size 500m -srcfolder "Leksah" "$LEKSAH_DMG" || exit
 
diff --git a/scripts/clean.sh b/scripts/clean.sh
--- a/scripts/clean.sh
+++ b/scripts/clean.sh
@@ -15,6 +15,7 @@
 ghc-pkg$GHCVERSION unregister --force webkit || true
 ghc-pkg$GHCVERSION unregister --force webkitgtk3 || true
 ghc-pkg$GHCVERSION unregister --force gtk-mac-integration || true
+ghc-pkg$GHCVERSION unregister --force gtk3-mac-integration || true
 ghc-pkg$GHCVERSION unregister --force gtk || true
 ghc-pkg$GHCVERSION unregister --force gtk3 || true
 ghc-pkg$GHCVERSION unregister --force pango || true
diff --git a/scripts/stage.sh b/scripts/stage.sh
--- a/scripts/stage.sh
+++ b/scripts/stage.sh
@@ -16,9 +16,15 @@
 
 echo Staging Leksah in $GTK_PREFIX
 
+# cabal sandbox init || true
+# (cd vendor/yi/yi && cabal sandbox init --sandbox=../../../.cabal-sandbox) || true
+# (cd vendor/ltk && cabal sandbox init --sandbox=../../.cabal-sandbox) || true
+# (cd vendor/leksah-server && cabal sandbox init --sandbox=../../.cabal-sandbox) || true
+# cabal sandbox add-source ./vendor/ltk ./vendor/leksah-server ./vendor/yi/yi || true
+
 # These don't like all the extra options we pass (CPPFLAGS and --extra-lib-dirs)
 # Gtk2Hs needs the latest Cabal to install properly
-cabal install --with-ghc=ghc$GHCVERSION -j4 text parsec network uniplate Cabal --constraint='text>=0.11.3.1' --constraint='parsec>=3.1.3' || true
+# cabal install --with-ghc=ghc$GHCVERSION -j4 text parsec network uniplate Cabal --constraint='text>=0.11.3.1' --constraint='parsec>=3.1.3' --constraint='ghc -any' || true
 
 # Needed for installing curl package on windows
 export CPPFLAGS=`pkg-config --cflags-only-I libcurl`
@@ -26,21 +32,10 @@
 # Only used by OS X
 # export DYLD_LIBRARY_PATH="/System/Library/Frameworks/ApplicationServices.framework/Versions/A/Frameworks/ImageIO.framework/Versions/A/Resources:$GTK_PREFIX/lib:$DYLD_LIBRARY_PATH"
 
-echo https://github.com/leksah/ltk > sources.txt
-echo https://github.com/leksah/leksah-server >> sources.txt
-
-# echo ./vendor/gtk2hs >> sources.txt
-echo ./ >> sources.txt
-
 if test "`uname`" = "Darwin"; then
-    cabal install gtk3 ghcjs-dom jsaddle --with-ghc=ghc$GHCVERSION -j4 -fhave-quartz-gtk -fwebkit --with-gcc=gcc-mp-4.8 || exit
-    cabal-meta install --with-ghc=ghc$GHCVERSION -j4 -flibcurl --with-gcc=gcc-mp-4.8 || exit
+    cabal install ./ ./vendor/ltk ./vendor/leksah-server ./vendor/yi/yi gtk3 ghcjs-dom jsaddle vendor/haskellVCSWrapper/vcswrapper vendor/haskellVCSGUI/vcsgui --with-ghc=ghc$GHCVERSION -j4 -fhave-quartz-gtk -fwebkit -flibcurl -fyi -fpango --with-gcc=gcc-mp-4.8 || exit
 else
-    HPDIR=`which ghc` || exit
-    HPDIR=`dirname "$HPDIR"` || exit
-    HPDIR=`dirname "$HPDIR"` || exit
-    cabal install gtk3 ghcjs-dom jsaddle --with-ghc=ghc$GHCVERSION -j4 --extra-lib-dirs="$HPDIR"/mingw/lib --extra-lib-dirs=/c/MinGWRPM/lib -fwebkit --force-reinstalls || bash || exit
-    cabal-meta install --with-ghc=ghc$GHCVERSION -j4 --extra-lib-dirs="$HPDIR"/mingw/lib --extra-lib-dirs=/c/MinGWRPM/lib -flibcurl --force-reinstalls || bash || exit
+    cabal install ./ ./vendor/ltk ./vendor/leksah-server ./vendor/yi/yi gtk3 ghcjs-dom jsaddle vendor/haskellVCSWrapper/vcswrapper vendor/haskellVCSGUI/vcsgui --with-ghc=ghc$GHCVERSION -j4 -fwebkit -flibcurl --force-reinstalls || bash || exit
 #  if [ "$GHC_VER" != "7.0.3" ] && [ "$GHC_VER" != "7.0.4" ] && [ "$GHC_VER" != "7.6.1" ]; then
 #    echo https://github.com/yi-editor/yi.git >> sources.txt
 #    export LEKSAH_CONFIG_ARGS="$LEKSAH_CONFIG_ARGS -fyi -f-vty -f-dyre -fpango"
diff --git a/src/IDE/BufferMode.hs b/src/IDE/BufferMode.hs
--- a/src/IDE/BufferMode.hs
+++ b/src/IDE/BufferMode.hs
@@ -1,4 +1,11 @@
-{-# LANGUAGE CPP, FlexibleInstances, DeriveDataTypeable, TypeSynonymInstances, MultiParamTypeClasses, Rank2Types, GADTs, FlexibleContexts, ScopedTypeVariables #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ExistentialQuantification #-}
+{-# LANGUAGE Rank2Types #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.BufferMode
@@ -40,7 +47,10 @@
 #if MIN_VERSION_directory(1,2,0)
 import Data.Time (UTCTime)
 #endif
-
+import Data.Text (Text)
+import Data.Monoid ((<>))
+import qualified Data.Text as T
+       (isPrefixOf, lines, unlines, count, isInfixOf)
 
 -- * Buffer Basics
 
@@ -49,7 +59,7 @@
 --
 data IDEBuffer = forall editor. TextEditor editor => IDEBuffer {
     fileName        ::  Maybe FilePath
-,   bufferName      ::  String
+,   bufferName      ::  Text
 ,   addedIndex      ::  Int
 ,   sourceView      ::  EditorView editor
 ,   scrolledWindow  ::  ScrolledWindow
@@ -69,7 +79,7 @@
     paneId b        =   ""
 
 data BufferState            =   BufferState FilePath Int
-                            |   BufferStateTrans String String Int
+                            |   BufferStateTrans Text Text Int
     deriving(Eq,Ord,Read,Show,Typeable)
 
 maybeActiveBuf :: IDEM (Maybe IDEBuffer)
@@ -118,7 +128,7 @@
     mbI            <-  liftIO $ notebookPageNum nb (scrolledWindow ideBuf)
     case mbI of
         Nothing ->  liftIO $ do
-            sysMessage Normal $ bufferName ideBuf ++ " notebook page not found: unexpected"
+            sysMessage Normal $ bufferName ideBuf <> " notebook page not found: unexpected"
             return def
         Just i  ->  do
             ebuf <- liftIDE $ getBuffer v
@@ -140,16 +150,16 @@
 -- * Buffer Modes
 
 data Mode = Mode {
-    modeName               :: String,
+    modeName               :: Text,
     modeEditComment        :: IDEAction,
     modeEditUncomment      :: IDEAction,
-    modeSelectedModuleName :: IDEM (Maybe String),
-    modeEditToCandy        :: (String -> Bool) -> IDEAction,
-    modeTransformToCandy   :: TextEditor editor => (String -> Bool) -> EditorBuffer editor -> IDEAction,
+    modeSelectedModuleName :: IDEM (Maybe Text),
+    modeEditToCandy        :: (Text -> Bool) -> IDEAction,
+    modeTransformToCandy   :: TextEditor editor => (Text -> Bool) -> EditorBuffer editor -> IDEAction,
     modeEditFromCandy      :: IDEAction,
-    modeEditKeystrokeCandy :: Maybe Char -> (String -> Bool) -> IDEAction,
-    modeEditInsertCode     :: TextEditor editor => String -> EditorIter editor -> EditorBuffer editor -> IDEAction,
-    modeEditInCommentOrString :: String -> Bool
+    modeEditKeystrokeCandy :: Maybe Char -> (Text -> Bool) -> IDEAction,
+    modeEditInsertCode     :: TextEditor editor => Text -> EditorIter editor -> EditorBuffer editor -> IDEAction,
+    modeEditInCommentOrString :: Text -> Bool
     }
 
 
@@ -199,16 +209,9 @@
             keystrokeCandy ct c ebuf inCommentOrString,
     modeEditInsertCode = \ str iter buf ->
         insert buf iter str,
-    modeEditInCommentOrString = \ line ->
-            if isInfixOf "--" line
-                then True
-                else let indices = elemIndices '"' line
-                     in if length indices == 0
-                            then False
-                            else if even (length indices)
-                                then False
-                                else True
-}
+    modeEditInCommentOrString = \ line -> ("--" `T.isInfixOf` line)
+                                        || not (even $ T.count "\"" line)
+    }
 
 literalHaskellMode = Mode {
     modeName = "Literal Haskell",
@@ -250,16 +253,10 @@
         inActiveBufContext () $ \_ _ ebuf _ _ -> do
             keystrokeCandy ct c ebuf inCommentOrString,
     modeEditInsertCode = \ str iter buf ->
-        insert buf iter (unlines $ map (\ s -> "> " ++ s) $ lines str),
-    modeEditInCommentOrString = \ line ->
-            if not (isPrefixOf ">" line)
-                then True
-                else let indices = elemIndices '"' line
-                     in if length indices == 0
-                            then False
-                            else if even (length indices)
-                                then False
-                                else True  }
+        insert buf iter (T.unlines $ map (\ s -> "> " <> s) $ T.lines str),
+    modeEditInCommentOrString = \ line -> not (T.isPrefixOf ">" line)
+                                        || not (even $ T.count "\"" line)
+    }
 
 cabalMode = Mode {
     modeName                 = "Cabal",
@@ -283,7 +280,7 @@
     modeEditFromCandy        = return (),
     modeEditKeystrokeCandy   = \ _ _ -> return (),
     modeEditInsertCode       = \ str iter buf -> insert buf iter str,
-    modeEditInCommentOrString = \ str -> isPrefixOf "--" str
+    modeEditInCommentOrString = \ str -> T.isPrefixOf "--" str
 
     }
 
@@ -315,7 +312,7 @@
 editUncomment :: IDEAction
 editUncomment      = withCurrentMode () modeEditUncomment
 
-selectedModuleName  :: IDEM (Maybe String)
+selectedModuleName  :: IDEM (Maybe Text)
 selectedModuleName = withCurrentMode Nothing modeSelectedModuleName
 
 editToCandy :: IDEAction
@@ -328,7 +325,7 @@
 editKeystrokeCandy c = withCurrentMode () (\m -> modeEditKeystrokeCandy m c
                             (modeEditInCommentOrString m))
 
-editInsertCode :: TextEditor editor => EditorBuffer editor -> EditorIter editor -> String -> IDEAction
+editInsertCode :: TextEditor editor => EditorBuffer editor -> EditorIter editor -> Text -> IDEAction
 editInsertCode buffer iter str = withCurrentMode ()
                                             (\ m -> modeEditInsertCode m str iter buffer)
 
diff --git a/src/IDE/Build.hs b/src/IDE/Build.hs
--- a/src/IDE/Build.hs
+++ b/src/IDE/Build.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC #-}
 -----------------------------------------------------------------------------
 --
@@ -40,12 +41,15 @@
         packageTest', packageDoc')
 import IDE.Core.Types
        (IDEEvent(..), Prefs(..), IDE(..), WorkspaceAction)
-import Distribution.Text (Text(..))
 import Control.Event (EventSource(..))
 import Control.Monad.Trans.Reader (ask)
 import Control.Monad.Trans.Class (MonadTrans(..))
 import Control.Monad (void)
 import Control.Arrow ((***))
+import Data.Text (Text)
+import Distribution.Text (disp)
+import Data.Monoid ((<>))
+import qualified Data.Text as T (pack, unpack)
 
 -- import Debug.Trace (trace)
 trace a b = b
@@ -80,7 +84,7 @@
     | MoRegister
     | MoClean
     | MoDocu
-    | MoOther String
+    | MoOther Text
     | MoMetaInfo -- rebuild meta info for workspace
     | MoComposed [MakeOp]
     deriving (Eq,Ord,Show)
@@ -130,7 +134,7 @@
 constrMakeChain ms@MakeSettings{msMakeMode = makeMode}
                     Workspace{wsPackages = packages, wsNobuildPack = noBuilds}
                     targets firstOp restOp finishOp =
-    trace ("topsorted: " ++ showTopSorted topsorted)
+    trace (T.unpack $ "topsorted: " <> showTopSorted topsorted)
     constrElem targets topsorted depGraph ms noBuilds
                     firstOp restOp finishOp False
   where
@@ -216,7 +220,7 @@
 -- | Construct a dependency graph for a package
 -- pointing to the packages the subject package depends on
 constrParentGraph :: [IDEPackage] -> MakeGraph
-constrParentGraph targets = trace ("parentGraph : " ++ showGraph parGraph) parGraph
+constrParentGraph targets = trace (T.unpack $ "parentGraph : " <> showGraph parGraph) parGraph
   where
     parGraph = Map.fromList
         $ map (\ p -> (p,nub $ mapMaybe (depToTarget targets)(ipdDepends p))) targets
@@ -224,18 +228,18 @@
 -- | Construct a dependency graph for a package
 -- pointing to the packages which depend on the subject package
 constrDepGraph :: [IDEPackage] -> MakeGraph
-constrDepGraph packages = trace ("depGraph : " ++ showGraph depGraph) depGraph
+constrDepGraph packages = trace (T.unpack $ "depGraph : " <> showGraph depGraph) depGraph
   where
     depGraph = reverseGraph (constrParentGraph packages)
 
-showGraph :: MakeGraph -> String
+showGraph :: MakeGraph -> Text
 showGraph mg =
-    show
+    T.pack $ show
         $ map (\(k,v) -> (disp (ipdPackageId k), map (disp . ipdPackageId) v))
             $ Map.toList mg
 
-showTopSorted :: [IDEPackage] -> String
-showTopSorted = show . map (disp .ipdPackageId)
+showTopSorted :: [IDEPackage] -> Text
+showTopSorted = T.pack . show . map (disp .ipdPackageId)
 
 
 -- | Calculates for every dependency a target (or not)
diff --git a/src/IDE/Command.hs b/src/IDE/Command.hs
--- a/src/IDE/Command.hs
+++ b/src/IDE/Command.hs
@@ -1,4 +1,6 @@
-{-# LANGUAGE ScopedTypeVariables, ForeignFunctionInterface #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -fno-warn-incomplete-patterns #-}
 -----------------------------------------------------------------------------
 --
@@ -104,7 +106,6 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad (unless, when)
 import Control.Monad.Trans.Reader (ask)
-import Text.Printf (printf)
 import System.Log.Logger (debugM)
 import Foreign.C.Types (CInt(..))
 import Foreign.Ptr (Ptr(..))
@@ -113,8 +114,16 @@
 import IDE.Session
        (saveSessionAs, loadSession, saveSession, sessionClosePane,
         loadSessionPrompt, saveSessionAsPrompt, viewFullScreen, viewDark)
-import qualified Data.Text as T (pack)
+import qualified Data.Text as T (unpack, pack)
+import Data.Text (Text)
+import qualified Data.Text.IO as T (readFile)
+import Data.Monoid (Monoid(..), (<>))
+import qualified Text.Printf as S (printf)
+import Text.Printf (PrintfType)
 
+printf :: PrintfType r => Text -> r
+printf = S.printf . T.unpack
+
 foreign import ccall safe "gtk_toolbar_set_icon_size"
   gtk_toolbar_set_icon_size :: Ptr Toolbar -> CInt -> IO ()
 
@@ -465,7 +474,7 @@
     ,AD "Help" (__ "_Help") Nothing Nothing (return ()) [] False
     ,AD "HelpDebug" (__ "Debug") Nothing Nothing (do
             pack <- readIDE activePack
-            ideMessage Normal (show pack)) [] False
+            ideMessage Normal (T.pack $ show pack)) [] False
 --    ,AD "HelpDebug2" "Debug2" (Just "<Ctrl>d") Nothing dbgInstalledPackageInfo [] False
     ,AD "HelpManual" (__ "Manual") Nothing Nothing (openBrowser "http://leksah.org/leksah_manual.pdf") [] False
     ,AD "HelpHomepage" (__ "Homepage") Nothing Nothing (openBrowser "http://leksah.org") [] False
@@ -486,11 +495,11 @@
 --
 -- | The menu description in XML Syntax as defined by GTK
 --
-menuDescription :: IO String
+menuDescription :: IO Text
 menuDescription = do
     dataDir     <- getDataDir
     prefsPath   <- getConfigFilePathForLoad "leksah.menu" Nothing dataDir
-    readFile prefsPath
+    T.readFile prefsPath
 
 updateRecentEntries :: IDEAction
 updateRecentEntries = do
@@ -503,7 +512,7 @@
         mapM_ (\s -> do
             fe <- doesFileExist s
             when fe $ do
-                mi <- menuItemNewWithLabel s
+                mi <- menuItemNewWithLabel $ T.pack s
                 mi `on` menuItemActivate $ reflectIDE (fileOpenThis s) ideR
                 menuShellAppend recentFilesMenu mi) recentFiles'
         oldSubmenu <- menuItemGetSubmenu recentFilesItem
@@ -516,7 +525,7 @@
         mapM_ (\s -> do
             fe <- doesFileExist s
             when fe $ do
-                mi <- menuItemNewWithLabel s
+                mi <- menuItemNewWithLabel $ T.pack s
                 mi `on` menuItemActivate $ reflectIDE (workspaceOpenThis True (Just s) >> showWorkspace) ideR
                 menuShellAppend recentWorkspacesMenu mi) recentWorkspaces'
         oldSubmenu <- menuItemGetSubmenu recentWorkspacesItem
@@ -530,9 +539,9 @@
 --
 -- | Building the Menu
 --
-makeMenu :: UIManager -> [ActionDescr IDERef] -> String -> IDEAction
+makeMenu :: UIManager -> [ActionDescr IDERef] -> Text -> IDEAction
 makeMenu uiManager actions menuDescription = reifyIDE (\ideR -> do
-    actionGroupGlobal <- actionGroupNew "global"
+    actionGroupGlobal <- actionGroupNew ("global" :: Text)
     mapM_ (actm ideR actionGroupGlobal) actions
     uiManagerInsertActionGroup uiManager actionGroupGlobal 1
     uiManagerAddUiFromString uiManager menuDescription
@@ -540,8 +549,8 @@
     where
         actm ideR ag (AD name label tooltip stockId ideAction accs isToggle) = do
             let (acc,accString) = if null accs
-                                    then (Just "", "=" ++ name)
-                                    else (Just (head accs), head accs ++ "=" ++ name)
+                                    then (Just "", "=" <> name)
+                                    else (Just (head accs), head accs <> "=" <> name)
             if isToggle
                 then do
                     act <- toggleActionNew name label tooltip stockId
@@ -560,11 +569,11 @@
 -- getMenuAndToolbars :: UIManager -> IO (AccelGroup, MenuBar, Toolbar)
 getMenuAndToolbars uiManager = do
     accGroup <- uiManagerGetAccelGroup uiManager
-    mbMenu   <- uiManagerGetWidget uiManager "/ui/menubar"
+    mbMenu   <- uiManagerGetWidget uiManager ("/ui/menubar" :: Text)
     let menu = case mbMenu of
                     Just it -> castToMenuBar it
                     Nothing -> throwIDE (__ "Menu>>makeMenu: failed to create menubar")
-    mbToolbar <- uiManagerGetWidget uiManager "/ui/toolbar"
+    mbToolbar <- uiManagerGetWidget uiManager ("/ui/toolbar" :: Text)
     let toolbar = case mbToolbar of
                     Just it -> castToToolbar it
                     Nothing -> throwIDE (__ "Menu>>makeMenu: failed to create toolbar")
@@ -658,15 +667,15 @@
 aboutDialog = do
     d <- aboutDialogNew
     dd <- getDataDir
-    license <- catch (readFile $ dd </> __ "LICENSE") (\ (_ :: SomeException) -> return "")
-    set d [ aboutDialogName := "Leksah"
-          , aboutDialogVersion := showVersion version
+    license <- catch (T.readFile $ dd </> T.unpack (__ "LICENSE")) (\ (_ :: SomeException) -> return "")
+    set d [ aboutDialogName := ("Leksah" :: Text)
+          , aboutDialogVersion := T.pack $ showVersion version
           , aboutDialogCopyright := __ "Copyright 2007-2011 Jürgen Nicklisch-Franken, Hamish Mackenzie"
-          , aboutDialogComments := __ "An integrated development environement (IDE) for the " ++
+          , aboutDialogComments := __ "An integrated development environement (IDE) for the " <>
                                __ "programming language Haskell and the Glasgow Haskell Compiler"
           , aboutDialogLicense := Just license
-          , aboutDialogWebsite := "http://leksah.org/"
-          , aboutDialogAuthors := ["Jürgen Nicklisch-Franken","Hamish Mackenzie"] ]
+          , aboutDialogWebsite := ("http://leksah.org/" :: Text)
+          , aboutDialogAuthors := ["Jürgen Nicklisch-Franken","Hamish Mackenzie" :: Text] ]
     dialogRun d
     widgetDestroy d
     return ()
@@ -683,12 +692,12 @@
             "ide_debug", "ide_step", "ide_local", "ide_module", "ide_continue", "ide_rebuild_meta",
             "ide_empty","ide_source_local", "ide_js"]
         iconFactoryAddDefault iconFactory)
-    (\(e :: SomeException) -> getDataDir >>= \dataDir -> throwIDE (printf (__ "Can't load icons from %s %s") dataDir (show e)))
+    (\(e :: SomeException) -> getDataDir >>= \dataDir -> throwIDE (T.pack $ printf (__ "Can't load icons from %s %s") dataDir (show e)))
     where
     loadIcon dataDir iconFactory name = do
-        pb      <-  pixbufNewFromFile $ dataDir </> "pics" </> (name ++ ".png")
+        pb      <-  pixbufNewFromFile $ dataDir </> "pics" </> (name <> ".png")
         icon    <-  iconSetNewFromPixbuf pb
-        iconFactoryAdd iconFactory name icon
+        iconFactoryAdd iconFactory (T.pack name) icon
 
 setSensitivity :: [(SensitivityMask, Bool)] -> IDEAction
 setSensitivity = mapM_ setSensitivitySingle
@@ -715,7 +724,7 @@
 getActionsFor SensitivityInterpreting = getActionsFor' ["QuitDebugger"]
 getActionsFor SensitivityWorkspaceOpen = return [] --TODO add here
 
-getActionsFor' :: [String] -> IDEM[Action]
+getActionsFor' :: [Text] -> IDEM[Action]
 getActionsFor' l = do
     r <- mapM getActionFor l
     return (catMaybes r)
@@ -724,7 +733,7 @@
             uiManager' <- getUiManager
             actionGroups <- liftIO $ uiManagerGetActionGroups uiManager'
             res <- liftIO $ actionGroupGetAction (head actionGroups) string
-            when (isNothing res) $ ideMessage Normal $ printf (__ "Can't find UI Action %s") string
+            when (isNothing res) $ ideMessage Normal $ T.pack $ printf (__ "Can't find UI Action %s") (T.unpack string)
             return res
 
 getAdditionalActionsFor :: SensitivityMask -> [Bool -> IDEAction]
@@ -752,7 +761,7 @@
         when iconExists $
             windowSetIconFromFile win iconPath
         vb <- vBoxNew False 1  -- Top-level vbox
-        widgetSetName vb "topBox"
+        widgetSetName vb ("topBox" :: Text)
         (acc,menu,toolbar) <-  getMenuAndToolbars uiManager'
         boxPackStart vb menu PackNatural 0
         boxPackStart vb toolbar PackNatural 0
@@ -821,7 +830,7 @@
                                 triggerEventIDE (StatusbarChanged [CompartmentCommand ""])
                                 return False
                             Just map -> do
-                                let sym = printMods mods ++ name
+                                let sym = printMods mods <> name
                                 triggerEventIDE (StatusbarChanged [CompartmentCommand sym])
                                 modifyIDE_ (\ide -> ide{specialKey = Just (map,sym)})
                                 return True
@@ -829,19 +838,19 @@
                         case Map.lookup (keyVal,sort mods) map of
                             Nothing -> do
                                 triggerEventIDE (StatusbarChanged [CompartmentCommand
-                                    (sym ++ printMods mods ++ name ++ "?")])
+                                    (sym <> printMods mods <> name <> "?")])
                                 return ()
                             Just (AD actname _ _ _ ideAction _ _) -> do
                                 triggerEventIDE (StatusbarChanged [CompartmentCommand
-                                    (sym ++ " " ++ printMods mods ++ name ++ "=" ++ actname)])
+                                    (sym <> " " <> printMods mods <> name <> "=" <> actname)])
                                 ideAction
                         modifyIDE_ (\ide -> ide{specialKey = Nothing})
                         return True
     where
-    printMods :: [Modifier] -> String
-    printMods = concatMap show
+    printMods :: [Modifier] -> Text
+    printMods = mconcat . map (T.pack . show)
 
-setSymbol :: String -> Bool -> IDEAction
+setSymbol :: Text -> Bool -> IDEAction
 setSymbol symbol openSource = do
     currentInfo' <- getWorkspaceInfo
     search <- getSearch Nothing
@@ -874,7 +883,7 @@
             postAsyncIDE $ do
                 log <- getLog
                 defaultLogLaunch <- getDefaultLogLaunch
-                liftIO $ appendLog log defaultLogLaunch (T.pack s) t
+                liftIO $ appendLog log defaultLogLaunch s t
                 return ()
             return e)
     registerEvent stRef "SelectInfo"
diff --git a/src/IDE/Command/Print.hs b/src/IDE/Command/Print.hs
--- a/src/IDE/Command/Print.hs
+++ b/src/IDE/Command/Print.hs
@@ -23,10 +23,12 @@
 import IDE.Core.Types
 import IDE.Core.State
 import IDE.Utils.Tool (readProcessWithExitCode)
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
 
 data PrintError = PrintError {
     exitCode :: Int
-    , stderr :: String
+    , stderr :: Text
     , printCmd :: FilePath
     } deriving (Read,Show)
 
@@ -37,10 +39,10 @@
 printCommand = "lpr"
 #endif
 
-print :: FilePath -> IO (Either PrintError String)
+print :: FilePath -> IO (Either PrintError Text)
 print fileName = do
         (ec, out, err) <- readProcessWithExitCode printCommand [fileName] ""
         case ec of
-                ExitSuccess -> return $ Right out
-                ExitFailure i -> return $ Left $ PrintError i err printCommand
+                ExitSuccess   -> return $ Right (T.pack out)
+                ExitFailure i -> return $ Left $ PrintError i (T.pack err) printCommand
 
diff --git a/src/IDE/Command/VCS/Common.hs b/src/IDE/Command/VCS/Common.hs
--- a/src/IDE/Command/VCS/Common.hs
+++ b/src/IDE/Command/VCS/Common.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Command.VCS.Common
@@ -20,6 +21,7 @@
 
 import IDE.Core.Types
 import IDE.Core.State
+import IDE.Utils.GUIUtils
 import qualified IDE.Utils.GUIUtils as GUIUtils
 import qualified IDE.Workspaces.Writer as Writer
 import qualified IDE.Command.VCS.Types as Types
@@ -37,6 +39,8 @@
 import qualified Control.Exception as Exc
 import Data.Maybe
 import qualified Data.Map as Map
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
 
 
 
@@ -48,7 +52,7 @@
                     (oldMenuItems,pw) <- readIDE vcsData
                     packageItem <-
                         case Map.lookup cabalFp oldMenuItems of
-                             Nothing -> liftIO $ Gtk.menuItemNewWithLabel cabalFp
+                             Nothing -> liftIO . Gtk.menuItemNewWithLabel $ T.pack cabalFp
                              Just menuItem -> return menuItem
                     let newMenuItems = Map.insert cabalFp packageItem oldMenuItems
                     modifyIDE_ (\ide -> ide {vcsData = (newMenuItems,pw)})
@@ -56,7 +60,7 @@
                     packageMenu <- liftIO Gtk.menuNew
 
                     -- build and set set-up repo action
-                    setupActionItem <- liftIO $ Gtk.menuItemNewWithMnemonic "_Setup Repo"
+                    setupActionItem <- liftIO $ Gtk.menuItemNewWithMnemonic (__"_Setup Repo")
                     liftIO $ setupActionItem `Gtk.on` Gtk.menuItemActivate $
                             reflectIDE (
                                     runSetupRepoActionWithContext cabalFp
@@ -83,7 +87,7 @@
                                  actionItem `Gtk.on` Gtk.menuItemActivate $
                                    reflectIDE (runActionWithContext action cabalFp) ideR
                                  Gtk.menuShellAppend packageMenu actionItem)
-                    mkVCSActions :: VCS.VCSType -> [(String, Types.VCSAction ())]
+                    mkVCSActions :: VCS.VCSType -> [(Text, Types.VCSAction ())]
                     mkVCSActions VCS.SVN = SVN.mkSVNActions
                     mkVCSActions VCS.GIT = GIT.mkGITActions
                     mkVCSActions VCS.Mercurial = Mercurial.mkMercurialActions
@@ -152,7 +156,7 @@
 
 
 -- | vcs conf for given package in current workspace.
-getVCSConf :: FilePath -> IDEM (Either String (Maybe VCSConf))
+getVCSConf :: FilePath -> IDEM (Either Text (Maybe VCSConf))
 getVCSConf pathToPackage = do
     mbWorkspace <- readIDE workspace
     case mbWorkspace of
@@ -160,7 +164,7 @@
         Just workspace -> getVCSConf' workspace pathToPackage
 
 -- | vcs conf for given package in given workspace.
-getVCSConf' :: Workspace -> FilePath -> IDEM (Either String (Maybe VCSConf))
+getVCSConf' :: Workspace -> FilePath -> IDEM (Either Text (Maybe VCSConf))
 getVCSConf' workspace pathToPackage = do
             let mbConfig = Map.lookup pathToPackage $ packageVcsConf workspace
             case mbConfig of
diff --git a/src/IDE/Command/VCS/Common/Workspaces.hs b/src/IDE/Command/VCS/Common/Workspaces.hs
--- a/src/IDE/Command/VCS/Common/Workspaces.hs
+++ b/src/IDE/Command/VCS/Common/Workspaces.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Command.VCS.Common.Workspaces
@@ -41,6 +42,8 @@
 import Data.Maybe
 import Data.List
 import System.Log.Logger (debugM)
+import Data.Monoid ((<>))
+import qualified Data.Text as T (unpack, pack)
 
 onWorkspaceClose :: IDEAction
 onWorkspaceClose = do
@@ -74,7 +77,7 @@
         eErrConf <- Common.getVCSConf' workspace fp
         case eErrConf of
             Left error -> do
-                liftIO $ putStrLn $ "Could not retrieve vcs-conf due to '"++error++"'."
+                liftIO . putStrLn . T.unpack $ "Could not retrieve vcs-conf due to '"<>error<>"'."
                 return (p, Nothing)
             Right mbConf -> case mbConf of
                                 Nothing -> do
diff --git a/src/IDE/Command/VCS/GIT.hs b/src/IDE/Command/VCS/GIT.hs
--- a/src/IDE/Command/VCS/GIT.hs
+++ b/src/IDE/Command/VCS/GIT.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Command.VCS.GIT
@@ -28,6 +29,7 @@
 
 import qualified VCSGui.Git as GitGUI
 import qualified VCSWrapper.Git as Git
+import Data.Text (Text)
 
 commitAction :: Types.VCSAction ()
 commitAction = Helper.createActionFromContext GitGUI.showCommitGUI
@@ -41,7 +43,7 @@
 pullAction :: Types.VCSAction ()
 pullAction = Helper.createActionFromContext $ GitGUI.askPassWrapper GitGUI.pull
 
-mkGITActions :: [(String, Types.VCSAction ())]
+mkGITActions :: [(Text, Types.VCSAction ())]
 mkGITActions = [
                 ("_Commit", commitAction)
                 ,("_View Log", viewLogAction)
diff --git a/src/IDE/Command/VCS/Mercurial.hs b/src/IDE/Command/VCS/Mercurial.hs
--- a/src/IDE/Command/VCS/Mercurial.hs
+++ b/src/IDE/Command/VCS/Mercurial.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Command.VCS.Mercurial
@@ -24,6 +25,7 @@
 
 import qualified VCSGui.Mercurial as MercurialGUI
 import qualified VCSWrapper.Mercurial as Mercurial
+import Data.Text (Text)
 
 commitAction :: Types.VCSAction ()
 commitAction = Helper.createActionFromContext MercurialGUI.showCommitGUI
@@ -37,7 +39,7 @@
 pullAction :: Types.VCSAction ()
 pullAction = Helper.createActionFromContext Mercurial.pull
 
-mkMercurialActions :: [(String, Types.VCSAction ())]
+mkMercurialActions :: [(Text, Types.VCSAction ())]
 mkMercurialActions = [
                 ("_Commit", commitAction)
                 ,("_View Log", viewLogAction)
diff --git a/src/IDE/Command/VCS/SVN.hs b/src/IDE/Command/VCS/SVN.hs
--- a/src/IDE/Command/VCS/SVN.hs
+++ b/src/IDE/Command/VCS/SVN.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Command.VCS.SVN
@@ -36,6 +37,7 @@
 import Control.Monad.Reader(liftIO,ask,lift)
 import Data.IORef(atomicModifyIORef, IORef)
 import Data.Either
+import Data.Text (Text)
 
 commitAction :: Types.VCSAction ()
 commitAction = do
@@ -52,7 +54,7 @@
 viewLogAction :: Types.VCSAction ()
 viewLogAction = createSVNActionFromContext GUISvn.showLogGUI
 
-mkSVNActions :: [(String, Types.VCSAction ())]
+mkSVNActions :: [(Text, Types.VCSAction ())]
 mkSVNActions = [
                 ("_Commit", commitAction)
                 ,("_View Log", viewLogAction)
@@ -61,7 +63,7 @@
 
 --HELPERS
 
-createSVNActionFromContext :: (Either GUISvn.Handler (Maybe String)
+createSVNActionFromContext :: (Either GUISvn.Handler (Maybe Text)
                                 -> Wrapper.Ctx())
                            -> Types.VCSAction ()
 createSVNActionFromContext action = do
@@ -71,7 +73,7 @@
             Nothing -> Helper.createActionFromContext $ action $ Left $ passwordHandler ide mergeInfo
             Just mb -> Helper.createActionFromContext $ action $ Right mb
     where
---        passwordHandler :: IORef IDE-> Maybe MergeId -> ((Maybe (Bool, Maybe String)) -> Wrapper.Ctx ())
+--        passwordHandler :: IORef IDE-> Maybe MergeId -> ((Maybe (Bool, Maybe Text)) -> Wrapper.Ctx ())
         passwordHandler ide mbMergeInfo result = liftIO $
             case result of
                 Just (True, pw) -> modifyIDE_' ide (\ide -> ide {vcsData = (mbMergeInfo, Just pw) })
diff --git a/src/IDE/Completion.hs b/src/IDE/Completion.hs
--- a/src/IDE/Completion.hs
+++ b/src/IDE/Completion.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, ScopedTypeVariables #-}
+{-# LANGUAGE CPP, ScopedTypeVariables, OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Completion
@@ -32,6 +32,10 @@
 import Control.Monad.Trans.Class (MonadTrans(..))
 import Control.Applicative ((<$>))
 import IDE.Utils.GUIUtils (getDarkState)
+import Data.Text (Text)
+import qualified Data.Text as T
+       (empty, commonPrefixes, pack, unpack, null, stripPrefix,
+        isPrefixOf)
 
 complete :: TextEditor editor => EditorView editor -> Bool -> IDEAction
 complete sourceView always = do
@@ -73,7 +77,7 @@
     eol <- forwardToLineEndC end
     line <- getSlice buffer sol eol False
 
-    let isImport = "import " `isPrefixOf` line
+    let isImport = "import " `T.isPrefixOf` line
         isIdent a = isAlphaNum a || a == '\'' || a == '_'  || (isImport && a == '.')
         isOp    a = isSymbol   a || a == ':'  || a == '\\' || a == '*' || a == '/' || a == '-'
                                  || a == '!'  || a == '@'  || a == '%' || a == '&' || a == '?'
@@ -120,7 +124,7 @@
                     fontDescriptionFromString str
                 Nothing -> do
                     f <- fontDescriptionNew
-                    fontDescriptionSetFamily f "Monospace"
+                    fontDescriptionSetFamily f ("Monospace" :: Text)
                     return f
             liftIO $ widgetModifyFont tree (Just font)
 
@@ -167,7 +171,7 @@
                 completion = ((width, height), Just (CompletionWindow window tree store))})
             updateOptions window tree store sourceView cids isWordChar always
 
-addEventHandling :: TextEditor editor => Window -> EditorView editor -> TreeView -> ListStore String
+addEventHandling :: TextEditor editor => Window -> EditorView editor -> TreeView -> ListStore Text
                  -> (Char -> Bool) -> Bool -> IDEM Connections
 addEventHandling window sourceView tree store isWordChar always = do
     ideR      <- ask
@@ -308,7 +312,7 @@
 
     return $ concat [cidsPress, cidsRelease, [ConnectC idButtonPress, ConnectC idMotion, ConnectC idButtonRelease, ConnectC idSelected]]
 
-withWord :: ListStore String -> TreePath -> (String -> IDEM ()) -> IDEM ()
+withWord :: ListStore Text -> TreePath -> (Text -> IDEM ()) -> IDEM ()
 withWord store treePath f = (do
    case treePath of
        [row] -> (do
@@ -318,41 +322,41 @@
        _ -> return ()
    )
 
-replaceWordStart :: TextEditor editor => EditorView editor -> (Char -> Bool) -> String -> IDEM ()
+replaceWordStart :: TextEditor editor => EditorView editor -> (Char -> Bool) -> Text -> IDEM ()
 replaceWordStart sourceView isWordChar name = do
     buffer <- getBuffer sourceView
     (selStart, selEnd) <- getSelectionBounds buffer
     start <- findWordStart selStart isWordChar
     wordStart <- getText buffer start selEnd True
-    case stripPrefix wordStart name of
+    case T.stripPrefix wordStart name of
         Just extra -> do
             end <- findWordEnd selEnd isWordChar
             wordFinish <- getText buffer selEnd end True
-            case (wordFinish, stripPrefix wordFinish extra) of
-                (_:_,Just extra2) -> do
+            case T.stripPrefix wordFinish extra of
+                Just extra2 | not (T.null wordFinish) -> do
                     selectRange buffer end end
                     insert buffer end extra2
-                _                 -> insert buffer selEnd extra
-        Nothing    -> return ()
+                _ -> insert buffer selEnd extra
+        Nothing -> return ()
 
-cancelCompletion :: Window -> TreeView -> ListStore String -> Connections -> IDEAction
+cancelCompletion :: Window -> TreeView -> ListStore Text -> Connections -> IDEAction
 cancelCompletion window tree store connections = do
     liftIO (do
-        listStoreClear (store :: ListStore String)
+        listStoreClear (store :: ListStore Text)
         signalDisconnectAll connections
         widgetHide window
         )
     modifyIDE_ (\ide -> ide{currentState = IsRunning})
 
-updateOptions :: forall editor. TextEditor editor => Window -> TreeView -> ListStore String -> EditorView editor -> Connections -> (Char -> Bool) -> Bool -> IDEAction
+updateOptions :: forall editor. TextEditor editor => Window -> TreeView -> ListStore Text -> EditorView editor -> Connections -> (Char -> Bool) -> Bool -> IDEAction
 updateOptions window tree store sourceView connections isWordChar always = do
     result <- tryToUpdateOptions window tree store sourceView False isWordChar always
     when (not result) $ cancelCompletion window tree store connections
 
-tryToUpdateOptions :: TextEditor editor => Window -> TreeView -> ListStore String -> EditorView editor -> Bool -> (Char -> Bool) -> Bool -> IDEM Bool
+tryToUpdateOptions :: TextEditor editor => Window -> TreeView -> ListStore Text -> EditorView editor -> Bool -> (Char -> Bool) -> Bool -> IDEM Bool
 tryToUpdateOptions window tree store sourceView selectLCP isWordChar always = do
     ideR <- ask
-    liftIO $ listStoreClear (store :: ListStore String)
+    liftIO $ listStoreClear (store :: ListStore Text)
     buffer <- getBuffer sourceView
     (selStart, end) <- getSelectionBounds buffer
     start <- findWordStart selStart isWordChar
@@ -382,10 +386,11 @@
         Nothing -> forwardToLineEndC iter
         Just we -> return we
 
-longestCommonPrefix (x:xs) (y:ys) | x == y = x : longestCommonPrefix xs ys
-longestCommonPrefix _ _ = []
+longestCommonPrefix a b = case T.commonPrefixes a b of
+                            Nothing        -> T.empty
+                            Just (p, _, _) -> p
 
-processResults :: TextEditor editor => Window -> TreeView -> ListStore String -> EditorView editor -> String -> [String]
+processResults :: TextEditor editor => Window -> TreeView -> ListStore Text -> EditorView editor -> Text -> [Text]
                -> Bool -> (Char -> Bool) -> Bool -> IDEAction
 processResults window tree store sourceView wordStart options selectLCP isWordChar always = do
     case options of
@@ -399,14 +404,13 @@
             newWordStart <- do
                 if selectLCP && currentWordStart == wordStart && (not $ null options)
                     then do
-                        let lcp = foldl1 longestCommonPrefix options
-                        return lcp
+                        return $ foldl1 longestCommonPrefix options
                     else
                         return currentWordStart
 
-            when (isPrefixOf wordStart newWordStart) $ do
+            when (T.isPrefixOf wordStart newWordStart) $ do
                 liftIO $ listStoreClear store
-                let newOptions = List.filter (isPrefixOf newWordStart) options
+                let newOptions = List.filter (T.isPrefixOf newWordStart) options
                 liftIO $ forM_ (take 200 newOptions) (listStoreAppend store)
                 Rectangle startx starty width height <- getIterLocation sourceView start
                 (wWindow, hWindow)                   <- liftIO $ windowGetSize window
diff --git a/src/IDE/Core/State.hs b/src/IDE/Core/State.hs
--- a/src/IDE/Core/State.hs
+++ b/src/IDE/Core/State.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE UndecidableInstances #-}
 {-# LANGUAGE FlexibleInstances, FlexibleContexts, TypeSynonymInstances,
              MultiParamTypeClasses, ScopedTypeVariables, CPP,
-             DeriveDataTypeable #-}
+             DeriveDataTypeable, OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Core.State
@@ -108,6 +108,9 @@
 import qualified Paths_leksah as P
 import System.Environment.Executable (getExecutablePath)
 import System.Directory (doesDirectoryExist)
+import Data.Text (Text)
+import qualified Data.Text as T (unpack)
+import Data.Monoid ((<>))
 
 instance PaneMonad IDEM where
     getFrameState   =   readIDE frameState
@@ -188,7 +191,7 @@
         where
             updateRecent (ide@IDE{currentState = IsFlipping _}) = ide
             updateRecent ide = ide{recentPanes = paneName pane : filter (/= paneName pane) (recentPanes ide)}
-            trigger :: Maybe String -> Maybe String -> IDEAction
+            trigger :: Maybe Text -> Maybe Text -> IDEAction
             trigger s1 s2 = do
                 triggerEventIDE (RecordHistory (PaneSelected s1, PaneSelected s2))
                 triggerEventIDE (Sensitivity [(SensitivityEditor, False)])
@@ -200,7 +203,7 @@
         mbI             <-  liftIO $notebookPageNum nb (getTopWidget pane)
         case mbI of
             Nothing ->  liftIO $ do
-                error ("notebook page not found: unexpected " ++ paneName pane ++ " " ++ show panePath)
+                error ("notebook page not found: unexpected " ++ T.unpack (paneName pane) ++ " " ++ show panePath)
                 return False
             Just i  ->  do
                 deactivatePaneIfActive pane
@@ -216,20 +219,20 @@
 
 
 -- Shall be replaced
-sysMessage :: MonadIO m =>  MessageLevel -> String -> m ()
+sysMessage :: MonadIO m =>  MessageLevel -> Text -> m ()
 sysMessage ml str = liftIO $ do
-    putStrLn str
+    putStrLn $ T.unpack str
     hFlush stdout
 
-ideMessage :: MonadIDE m => MessageLevel -> String -> m ()
+ideMessage :: MonadIDE m => MessageLevel -> Text -> m ()
 ideMessage level str = do
     liftIO $ sysMessage level str
-    triggerEventIDE (LogMessage (str ++ "\n") LogTag)
+    triggerEventIDE (LogMessage (str <> "\n") LogTag)
     return ()
 
-logMessage :: MonadIDE m => String -> LogTag -> m ()
+logMessage :: MonadIDE m => Text -> LogTag -> m ()
 logMessage str tag = do
-    triggerEventIDE (LogMessage (str ++ "\n") tag)
+    triggerEventIDE (LogMessage (str <> "\n") tag)
     return ()
 -- with hslogger
 
@@ -237,11 +240,11 @@
 ---- Exception handling
 ----
 
-data IDEException = IDEException String
+data IDEException = IDEException Text
     deriving Typeable
 
 instance Show IDEException where
-  show (IDEException str) = str
+  show (IDEException str) = T.unpack str
 
 instance Exception IDEException
 
diff --git a/src/IDE/Core/Types.hs b/src/IDE/Core/Types.hs
--- a/src/IDE/Core/Types.hs
+++ b/src/IDE/Core/Types.hs
@@ -1,15 +1,9 @@
-{-# LANGUAGE
-        CPP
-      , DisambiguateRecordFields
-      , ExistentialQuantification
-      , Rank2Types
-      , FlexibleInstances
-      , DeriveDataTypeable
-      , FlexibleContexts
-      , DeriveDataTypeable
-      , TypeSynonymInstances
-      , MultiParamTypeClasses #-}
-
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Core.Data
@@ -155,7 +149,7 @@
 ,   prefs           ::   Prefs                   -- ^ configuration preferences
 ,   workspace       ::   Maybe Workspace         -- ^ may be a workspace (set of packages)
 ,   activePack      ::   Maybe IDEPackage
-,   activeExe       ::   Maybe String
+,   activeExe       ::   Maybe Text
 ,   bufferProjCache ::   Map FilePath [IDEPackage]
 ,   allLogRefs      ::   [LogRef]
 ,   currentEBC      ::   (Maybe LogRef, Maybe LogRef, Maybe LogRef)
@@ -164,10 +158,10 @@
 ,   packageInfo     ::   (Maybe (GenScope, GenScope)) -- ^ the second are the imports
 ,   workspaceInfo   ::   (Maybe (GenScope, GenScope)) -- ^ the second are the imports
 ,   workspInfoCache ::   PackageDescrCache
-,   handlers        ::   Map String [(Unique, IDEEvent -> IDEM IDEEvent)] -- ^ event handling table
+,   handlers        ::   Map Text [(Unique, IDEEvent -> IDEM IDEEvent)] -- ^ event handling table
 ,   currentState    ::   IDEState
 ,   guiHistory      ::   (Bool,[GUIHistory],Int)
-,   findbar         ::   (Bool,Maybe (Toolbar,ListStore String))
+,   findbar         ::   (Bool,Maybe (Toolbar,ListStore Text))
 ,   toolbar         ::   (Bool,Maybe Toolbar)
 ,   recentFiles     ::   [FilePath]
 ,   recentWorkspaces ::  [FilePath]
@@ -176,10 +170,10 @@
 ,   completion      ::   ((Int, Int), Maybe CompletionWindow)
 ,   yiControl       ::   Yi.Control
 ,   server          ::   Maybe Handle
-,   vcsData         ::   (Map FilePath MenuItem, Maybe (Maybe String)) -- menus for packages, password
-,   logLaunches     ::   Map.Map String LogLaunchData
+,   vcsData         ::   (Map FilePath MenuItem, Maybe (Maybe Text)) -- menus for packages, password
+,   logLaunches     ::   Map.Map Text LogLaunchData
 ,   autoCommand     ::   IDEAction
-,   autoURI         ::   Maybe String
+,   autoURI         ::   Maybe Text
 } --deriving Show
 
 --
@@ -275,12 +269,12 @@
 data IDEEvent  =
         InfoChanged Bool-- is it the initial = True else False
     |   UpdateWorkspaceInfo
-    |   SelectInfo String Bool -- navigate to source (== True)
+    |   SelectInfo Text Bool -- navigate to source (== True)
     |   SelectIdent Descr
-    |   LogMessage String LogTag
+    |   LogMessage Text LogTag
     |   RecordHistory GUIHistory
     |   Sensitivity [(SensitivityMask,Bool)]
-    |   SearchMeta String
+    |   SearchMeta Text
     |   StartFindInitial
     |   GotoDefinition Descr
     |   LoadSession FilePath
@@ -296,7 +290,7 @@
     |   StatusbarChanged [StatusbarCompartment]
     |   WorkspaceChanged Bool Bool -- ^ showPane updateFileCache
 
-instance Event IDEEvent String where
+instance Event IDEEvent Text where
     getSelector (InfoChanged _)         =   "InfoChanged"
     getSelector UpdateWorkspaceInfo     =   "UpdateWorkspaceInfo"
     getSelector (LogMessage _ _)        =   "LogMessage"
@@ -320,7 +314,7 @@
     getSelector (StatusbarChanged _)    =   "StatusbarChanged"
     getSelector (WorkspaceChanged _ _)  =   "WorkspaceChanged"
 
-instance EventSource IDERef IDEEvent IDEM String where
+instance EventSource IDERef IDEEvent IDEM Text where
     canTriggerEvent _ "InfoChanged"         = True
     canTriggerEvent _ "UpdateWorkspaceInfo" = True
     canTriggerEvent _ "LogMessage"          = True
@@ -355,7 +349,7 @@
     myUnique _ = do
         liftIO $ newUnique
 
-instance EventSelector String
+instance EventSelector Text
 
 -- ---------------------------------------------------------------------
 -- IDEPackages
@@ -366,22 +360,22 @@
 ,   ipdDepends         ::   [Dependency]
 ,   ipdModules         ::   Map ModuleName BuildInfo
 ,   ipdHasLibs         ::   Bool
-,   ipdExes            ::   [String]
-,   ipdTests           ::   [String]
-,   ipdBenchmarks      ::   [String]
+,   ipdExes            ::   [Text]
+,   ipdTests           ::   [Text]
+,   ipdBenchmarks      ::   [Text]
 ,   ipdMain            ::   [(FilePath, BuildInfo, Bool)]
 ,   ipdExtraSrcs       ::   Set FilePath
 ,   ipdSrcDirs         ::   [FilePath]
 ,   ipdExtensions      ::   [Extension]
-,   ipdConfigFlags     ::   [String]
-,   ipdBuildFlags      ::   [String]
-,   ipdTestFlags       ::   [String]
-,   ipdHaddockFlags    ::   [String]
-,   ipdExeFlags        ::   [String]
-,   ipdInstallFlags    ::   [String]
-,   ipdRegisterFlags   ::   [String]
-,   ipdUnregisterFlags ::   [String]
-,   ipdSdistFlags      ::   [String]
+,   ipdConfigFlags     ::   [Text]
+,   ipdBuildFlags      ::   [Text]
+,   ipdTestFlags       ::   [Text]
+,   ipdHaddockFlags    ::   [Text]
+,   ipdExeFlags        ::   [Text]
+,   ipdInstallFlags    ::   [Text]
+,   ipdRegisterFlags   ::   [Text]
+,   ipdUnregisterFlags ::   [Text]
+,   ipdSdistFlags      ::   [Text]
 ,   ipdSandboxSources  ::   [IDEPackage]
 }
     deriving (Eq)
@@ -403,13 +397,13 @@
 --
 data Workspace = Workspace {
     wsVersion       ::   Int
-,   wsSaveTime      ::   String
-,   wsName          ::   String
+,   wsSaveTime      ::   Text
+,   wsName          ::   Text
 ,   wsFile          ::   FilePath
 ,   wsPackages      ::   [IDEPackage]
 ,   wsPackagesFiles ::   [FilePath]
 ,   wsActivePackFile::   Maybe FilePath
-,   wsActiveExe     ::   Maybe String
+,   wsActiveExe     ::   Maybe Text
 ,   wsNobuildPack   ::   [IDEPackage]
 ,   packageVcsConf  ::   Map FilePath VCSConf -- ^ (FilePath to package, Version-Control-System Configuration)
 } deriving Show
@@ -428,49 +422,49 @@
 --
 data ActionDescr alpha = AD {
     name        ::   ActionString
-,   label       ::   String
-,   tooltip     ::   Maybe String
-,   stockID     ::   Maybe String
+,   label       ::   Text
+,   tooltip     ::   Maybe Text
+,   stockID     ::   Maybe Text
 ,   action      ::   ReaderT alpha IO ()
 ,   accelerator ::   [KeyString]
 ,   isToggle    ::   Bool
 }
 
-type ActionString = String
-type KeyString = String
+type ActionString = Text
+type KeyString = Text
 
 --
 -- | Preferences is a data structure to hold configuration data
 --
 data Prefs = Prefs {
         prefsFormat         ::   Int
-    ,   prefsSaveTime       ::   String
+    ,   prefsSaveTime       ::   Text
     ,   showLineNumbers     ::   Bool
     ,   rightMargin         ::   (Bool, Int)
     ,   tabWidth            ::   Int
     ,   wrapLines           ::   Bool
-    ,   sourceCandy         ::   (Bool,String)
-    ,   keymapName          ::   String
+    ,   sourceCandy         ::   (Bool,Text)
+    ,   keymapName          ::   Text
     ,   forceLineEnds       ::   Bool
     ,   removeTBlanks       ::   Bool
-    ,   textviewFont        ::   Maybe String
-    ,   sourceStyle         ::   (Bool, String)
+    ,   textviewFont        ::   Maybe Text
+    ,   sourceStyle         ::   (Bool, Text)
     ,   foundBackground     ::   Color
     ,   matchBackground     ::   Color
     ,   contextBackground   ::   Color
     ,   breakpointBackground ::  Color
     ,   autoLoad            ::   Bool
-    ,   textEditor          ::   String
-    ,   logviewFont         ::   Maybe String
+    ,   textEditorType      ::   Text
+    ,   logviewFont         ::   Maybe Text
     ,   defaultSize         ::   (Int,Int)
-    ,   browser             ::   String
-    ,   pathForCategory     ::   [(String, PanePath)]
+    ,   browser             ::   Text
+    ,   pathForCategory     ::   [(Text, PanePath)]
     ,   defaultPath         ::   PanePath
-    ,   categoryForPane     ::   [(String, String)]
+    ,   categoryForPane     ::   [(Text, Text)]
     ,   packageBlacklist    ::   [Dependency]
     ,   collectAtStart      ::   Bool
     ,   useCtrlTabFlipping  ::   Bool
-    ,   docuSearchURL       ::   String
+    ,   docuSearchURL       ::   Text
     ,   completeRestricted  ::   Bool
     ,   saveAllBeforeBuild  ::   Bool
     ,   jumpToWarnings      ::   Bool
@@ -485,17 +479,17 @@
     ,   breakOnException    ::   Bool
     ,   breakOnError        ::   Bool
     ,   printBindResult     ::   Bool
-    ,   serverIP            ::   String
+    ,   serverIP            ::   Text
             -- As well used by server
     ,   serverPort          ::   Int
     ,   sourceDirectories   ::   [FilePath]
     ,   unpackDirectory     ::   Maybe FilePath
-    ,   retrieveURL         ::   String
+    ,   retrieveURL         ::   Text
     ,   retrieveStrategy    ::   RetrieveStrategy
     ,   endWithLastConn     ::   Bool
 } deriving(Eq,Show)
 
-cabalCommand :: Prefs -> String
+cabalCommand :: Prefs -> FilePath
 cabalCommand p = if useCabalDev p then "cabal-dev" else "cabal"
 
 data SearchHint = Forward | Backward | Insert | Delete | Initial
@@ -572,16 +566,16 @@
 
 newtype CandyTable      =   CT (CandyTableForth,CandyTableBack)
 
-type CandyTableForth    =   [(Bool,String,String)]
+type CandyTableForth    =   [(Bool,Text,Text)]
 
-type CandyTableBack     =   [(String,String,Int)]
+type CandyTableBack     =   [(Text,Text,Int)]
 
 newtype KeymapI         =   KM  (Map ActionString
-                                [(Maybe (Either KeyString (KeyString,KeyString)), Maybe String)])
+                                [(Maybe (Either KeyString (KeyString,KeyString)), Maybe Text)])
 
 type SpecialKeyTable alpha  =   Map (KeyVal,[Modifier]) (Map (KeyVal,[Modifier]) (ActionDescr alpha))
 
-type SpecialKeyCons  alpha  =   Maybe ((Map (KeyVal,[Modifier]) (ActionDescr alpha)),String)
+type SpecialKeyCons  alpha  =   Maybe ((Map (KeyVal,[Modifier]) (ActionDescr alpha)),Text)
 
 data LogTag = LogTag | ErrorTag | FrameTag | InputTag | InfoTag
 
@@ -591,14 +585,14 @@
 data GUIHistory' =
         ModuleSelected  {
             moduleS :: Maybe ModuleName
-        ,   facetS  :: Maybe String}
+        ,   facetS  :: Maybe Text}
     |   ScopeSelected {
             scope   :: Scope
         ,   blacklist :: Bool}
     |   InfoElementSelected {
             mbInfo  :: Maybe Descr}
     |   PaneSelected {
-            paneN   :: Maybe (String)}
+            paneN   :: Maybe (Text)}
    deriving (Eq, Ord, Show)
 
 data SensitivityMask =
@@ -619,13 +613,13 @@
 data CompletionWindow = CompletionWindow {
     cwWindow :: Window,
     cwTreeView :: TreeView,
-    cwListStore :: ListStore String}
+    cwListStore :: ListStore Text}
 
 data StatusbarCompartment =
-        CompartmentCommand String
+        CompartmentCommand Text
     |   CompartmentPane (Maybe (IDEPane IDEM))
-    |   CompartmentPackage String
-    |   CompartmentState String
+    |   CompartmentPackage Text
+    |   CompartmentState Text
     |   CompartmentOverlay Bool
     |   CompartmentBufferPos (Int,Int)
     |   CompartmentBuild Bool
diff --git a/src/IDE/Debug.hs b/src/IDE/Debug.hs
--- a/src/IDE/Debug.hs
+++ b/src/IDE/Debug.hs
@@ -82,28 +82,28 @@
 import IDE.Workspaces (packageTry)
 import qualified Data.Conduit as C
 import qualified Data.Conduit.List as CL
-import qualified Data.Conduit.Util as CU
 import Control.Monad.Trans.Class (MonadTrans(..))
 import Control.Monad.Trans.Reader (ask)
 import Control.Monad.IO.Class (MonadIO(..))
-import Control.Applicative (Alternative(..))
+import Control.Applicative (Alternative(..), (<$>), (<*>))
 import Data.IORef (newIORef)
 import Data.Monoid ((<>), Monoid(..))
 import Data.Text (Text)
-import qualified Data.Text as T (isSuffixOf, unpack)
+import qualified Data.Text as T
+       (pack, lines, stripPrefix, unlines, isSuffixOf, unpack)
 import System.Exit (ExitCode(..))
 import IDE.Pane.WebKit.Output (loadOutputUri)
 
 -- | Get the last item
 sinkLast = CL.fold (\_ a -> Just a) Nothing
 
-debugCommand :: String -> C.Sink ToolOutput IDEM () -> DebugAction
+debugCommand :: Text -> C.Sink ToolOutput IDEM () -> DebugAction
 debugCommand command handler = do
     debugCommand' command handler
     lift $ triggerEventIDE VariablesChanged
     return ()
 
-debugCommand' :: String -> C.Sink ToolOutput IDEM () -> DebugAction
+debugCommand' :: Text -> C.Sink ToolOutput IDEM () -> DebugAction
 debugCommand' command handler = do
     ghci <- ask
     lift $ catchIDE (runDebug (executeDebugCommand command handler) ghci)
@@ -133,12 +133,12 @@
 -- > stripComments "-- > Wow this is meta"
 --
 -- > stripComments "-- This is still a comment"
-stripComments :: String -> String
-stripComments t = maybe t unlines $
-        mapM (stripPrefix "-- >>>") lines'
-    <|> mapM (stripPrefix "-- >") lines'
+stripComments :: Text -> Text
+stripComments t = maybe t T.unlines $
+        mapM (T.stripPrefix "-- >>>") lines'
+    <|> mapM (T.stripPrefix "-- >") lines'
   where
-    lines' = lines t
+    lines' = T.lines t
 
 debugExecuteSelection :: IDEAction
 debugExecuteSelection = do
@@ -149,10 +149,12 @@
                 debugSetLiberalScope
                 buffer <- liftIO $ newIORef mempty
                 debugCommand (stripComments text) $ do
-                    (_, _) <- CU.zipSinks sinkLast (logOutputPane text buffer)
+                    _ <- C.getZipSink $ const
+                        <$> C.ZipSink sinkLast
+                        <*> C.ZipSink (logOutputPane text buffer)
                     mbURI <- lift $ readIDE autoURI
                     case mbURI of
-                        Just uri -> lift . postSyncIDE $ loadOutputUri uri
+                        Just uri -> lift . postSyncIDE . loadOutputUri $ T.unpack uri
                         Nothing -> return ()
             modifyIDE_ $ \ide -> ide {autoCommand = command, autoURI = Nothing}
             command
@@ -165,8 +167,10 @@
         Just text -> packageTry $ tryDebug $ do
             debugSetLiberalScope
             debugCommand (stripComments text) $ do
-                (out, _) <- CU.zipSinks (CL.fold buildOutputString "") logOutputDefault
-                lift . insertTextAfterSelection . T.unpack $ " " <> out
+                out <- C.getZipSink $ const
+                        <$> C.ZipSink (CL.fold buildOutputString "")
+                        <*> C.ZipSink logOutputDefault
+                lift . insertTextAfterSelection $ " " <> out
         Nothing   -> ideMessage Normal "Please select some text in the editor to execute"
     where
     buildOutputString :: Text -> ToolOutput -> Text
@@ -179,13 +183,13 @@
     maybeModuleName <- lift selectedModuleName
     case maybeModuleName of
         Just moduleName ->
-            debugCommand (":module *" ++ moduleName) CL.sinkNull
+            debugCommand (":module *" <> moduleName) CL.sinkNull
         Nothing -> do
             mbPackage <- lift getActivePackageDescr
             case mbPackage of
                 Nothing -> return ()
-                Just p -> let packageNames = map (display . modu . mdModuleId) (pdModules p)
-                    in debugCommand' (foldl (\a b -> a ++ " *" ++ b) ":module + " packageNames)
+                Just p -> let packageNames = map (T.pack . display . modu . mdModuleId) (pdModules p)
+                    in debugCommand' (foldl (\a b -> a <> " *" <> b) ":module + " packageNames)
                         CL.sinkNull
 
 debugAbandon :: IDEAction
@@ -225,9 +229,9 @@
     packageTry $ tryDebug $ debugCommand ":delete *" logOutputDefault
     setBreakpointList []
 
-debugDeleteBreakpoint :: String -> LogRef -> IDEAction
+debugDeleteBreakpoint :: Text -> LogRef -> IDEAction
 debugDeleteBreakpoint indexString lr = do
-    packageTry $ tryDebug $ debugCommand (":delete " ++ indexString) logOutputDefault
+    packageTry $ tryDebug $ debugCommand (":delete " <> indexString) logOutputDefault
     bl <- readIDE breakpointRefs
     setBreakpointList $ filter (/= lr) bl
     ideR <- ask
@@ -237,7 +241,7 @@
 debugForce = do
     maybeText <- selectedTextOrCurrentLine
     case maybeText of
-        Just text -> packageTry $ tryDebug $ debugCommand (":force " ++ stripComments text) logOutputDefault
+        Just text -> packageTry $ tryDebug $ debugCommand (":force " <> stripComments text) logOutputDefault
         Nothing   -> ideMessage Normal "Please select an expression in the editor"
 
 debugHistory :: IDEAction
@@ -247,14 +251,14 @@
 debugPrint = do
     maybeText <- selectedTextOrCurrentLine
     case maybeText of
-        Just text -> packageTry $ tryDebug $ debugCommand (":print " ++ stripComments text) logOutputDefault
+        Just text -> packageTry $ tryDebug $ debugCommand (":print " <> stripComments text) logOutputDefault
         Nothing   -> ideMessage Normal "Please select an name in the editor"
 
 debugSimplePrint :: IDEAction
 debugSimplePrint = do
     maybeText <- selectedTextOrCurrentLine
     case maybeText of
-        Just text -> packageTry $ tryDebug $ debugCommand (":force " ++ stripComments text) logOutputDefault
+        Just text -> packageTry $ tryDebug $ debugCommand (":force " <> stripComments text) logOutputDefault
         Nothing   -> ideMessage Normal "Please select an name in the editor"
 
 debugStep :: IDEAction
@@ -270,11 +274,11 @@
         debugSetLiberalScope
         debugStepExpr maybeText
 
-debugStepExpr :: Maybe String -> DebugAction
+debugStepExpr :: Maybe Text -> DebugAction
 debugStepExpr maybeText = do
     (debugPackage, _) <- ask
     case maybeText of
-        Just text -> debugCommand (":step " ++ stripComments text) (logOutputForHistoricContextDefault debugPackage)
+        Just text -> debugCommand (":step " <> stripComments text) (logOutputForHistoricContextDefault debugPackage)
         Nothing   -> lift $ ideMessage Normal "Please select an expression in the editor"
 
 debugStepLocal :: IDEAction
@@ -305,11 +309,11 @@
         debugSetLiberalScope
         debugTraceExpr maybeText
 
-debugTraceExpr :: Maybe String -> DebugAction
+debugTraceExpr :: Maybe Text -> DebugAction
 debugTraceExpr maybeText = do
     (debugPackage, _) <- ask
     case maybeText of
-        Just text -> debugCommand (":trace " ++ stripComments text) $ logTraceOutput debugPackage
+        Just text -> debugCommand (":trace " <> stripComments text) $ logTraceOutput debugPackage
         Nothing   -> lift $ ideMessage Normal "Please select an expression in the editor"
 
 
@@ -351,7 +355,7 @@
     case maybeText of
         Just text -> packageTry $ tryDebug $ do
             debugSetLiberalScope
-            debugCommand (":info "++stripComments text) logOutputDefault
+            debugCommand (":info "<>stripComments text) logOutputDefault
         Nothing   -> ideMessage Normal "Please select a name in the editor"
 
 debugKind :: IDEAction
@@ -360,7 +364,7 @@
     case maybeText of
         Just text -> packageTry $ tryDebug $ do
             debugSetLiberalScope
-            debugCommand (":kind "++stripComments text) logOutputDefault
+            debugCommand (":kind "<>stripComments text) logOutputDefault
         Nothing   -> ideMessage Normal "Please select a type in the editor"
 
 debugType :: IDEAction
@@ -369,7 +373,7 @@
     case maybeText of
         Just text -> packageTry $ tryDebug $ do
             debugSetLiberalScope
-            debugCommand (":type "++stripComments text) logOutputDefault
+            debugCommand (":type "<>stripComments text) logOutputDefault
         Nothing   -> ideMessage Normal "Please select an expression in the editor"
 
 debugSetBreakpoint :: IDEAction
@@ -382,23 +386,23 @@
             case maybeText of
                 Just text -> packageTry $ tryDebug $ do
                     (debugPackage, _) <- ask
-                    debugCommand (":module *" ++ moduleName) logOutputDefault
-                    debugCommand (":break " ++ text) (logOutputForSetBreakpointDefault debugPackage)
+                    debugCommand (":module *" <> moduleName) logOutputDefault
+                    debugCommand (":break " <> text) (logOutputForSetBreakpointDefault debugPackage)
                 Nothing   -> do
                     maybeLocation <- selectedLocation
                     case maybeLocation of
                         Just (line, lineOffset) -> packageTry $ tryDebug $ do
                             (debugPackage, _) <- ask
-                            debugCommand (":break " ++ moduleName ++ " " ++ show (line + 1) ++ " " ++ show lineOffset)
+                            debugCommand (":break " <> moduleName <> " " <> T.pack (show $ line + 1) <> " " <> T.pack (show lineOffset))
                                          (logOutputForSetBreakpointDefault debugPackage)
                         Nothing -> ideMessage Normal "Unknown error setting breakpoint"
             ref <- ask
             return ()
         Nothing   -> ideMessage Normal "Please select module file in the editor"
 
-debugSet :: (Bool -> String) -> Bool -> IDEAction
+debugSet :: (Bool -> Text) -> Bool -> IDEAction
 debugSet flag value =
-    packageTry $ tryDebug $ debugCommand (":set " ++ flag value) logOutputDefault
+    packageTry $ tryDebug $ debugCommand (":set " <> flag value) logOutputDefault
 
 debugSetPrintEvldWithShow :: Bool -> IDEAction
 debugSetPrintEvldWithShow = debugSet printEvldWithShowFlag
diff --git a/src/IDE/Find.hs b/src/IDE/Find.hs
--- a/src/IDE/Find.hs
+++ b/src/IDE/Find.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE ForeignFunctionInterface #-}
 -----------------------------------------------------------------------------
 --
@@ -67,7 +69,7 @@
 import Data.Char (digitToInt, isDigit, toLower, isAlphaNum)
 import Text.Regex.TDFA hiding (caseSensitive, after)
 import qualified Text.Regex.TDFA as Regex
-import Text.Regex.TDFA.String (compile)
+import Text.Regex.TDFA.Text (compile)
 import Data.List (find, isPrefixOf)
 import Data.Array (bounds, (!), inRange)
 import IDE.Pane.Grep (grepWorkspace)
@@ -80,6 +82,10 @@
 import Foreign.Ptr (Ptr(..))
 import Foreign.ForeignPtr (withForeignPtr)
 import Graphics.UI.GtkInternals (unToolbar)
+import Data.Text (Text)
+import qualified Data.Text as T
+       (pack, unpack, singleton, isPrefixOf, length, null, toLower)
+import Data.Monoid ((<>))
 
 foreign import ccall safe "gtk_toolbar_set_icon_size"
   gtk_toolbar_set_icon_size :: Ptr Toolbar -> CInt -> IO ()
@@ -90,10 +96,10 @@
     \selfPtr ->gtk_toolbar_set_icon_size selfPtr (fromIntegral $ fromEnum iconSize)
 
 data FindState = FindState {
-            entryStr        ::    String
-        ,   entryHist       ::    [String]
-        ,   replaceStr      ::    String
-        ,   replaceHist     ::    [String]
+            entryStr        ::    Text
+        ,   entryHist       ::    [Text]
+        ,   replaceStr      ::    Text
+        ,   replaceHist     ::    [Text]
         ,   caseSensitive   ::    Bool
         ,   entireWord      ::    Bool
         ,   wrapAround      ::    Bool
@@ -203,13 +209,13 @@
 
     spinTool <- toolItemNew
     spinL <- spinButtonNewWithRange 1.0 1000.0 10.0
-    widgetSetName spinL "gotoLineEntry"
+    widgetSetName spinL ("gotoLineEntry" :: Text)
     containerAdd spinTool spinL
-    widgetSetName spinTool "gotoLineEntryTool"
+    widgetSetName spinTool ("gotoLineEntryTool" :: Text)
     toolbarInsert toolbar spinTool 0
 
     labelTool3 <- toolItemNew
-    label3 <- labelNew (Just "Goto Line :")
+    label3 <- labelNew (Just (__"Goto Line :"))
     containerAdd labelTool3 label3
     toolbarInsert toolbar labelTool3 0
 
@@ -217,15 +223,15 @@
     toolbarInsert toolbar sep1 0
 
     let performGrep = reflectIDE (packageTry $ doGrep toolbar) ideR
-    grepButton <- toolButtonNew (Nothing :: Maybe Widget) (Just "Grep")
+    grepButton <- toolButtonNew (Nothing :: Maybe Widget) (Just (__"Grep"))
     toolbarInsert toolbar grepButton 0
     grepButton `onToolButtonClicked` performGrep
-    set grepButton [widgetTooltipText := Just "Search in multiple files"]
+    set grepButton [widgetTooltipText := Just (__"Search in multiple files")]
 
     sep1 <- separatorToolItemNew
     toolbarInsert toolbar sep1 0
 
-    replaceAllButton <- toolButtonNew (Nothing :: Maybe Widget) (Just "Replace All")
+    replaceAllButton <- toolButtonNew (Nothing :: Maybe Widget) (Just (__"Replace All"))
     toolbarInsert toolbar replaceAllButton 0
 
     replaceButton <- toolButtonNewFromStock "gtk-find-and-replace"
@@ -233,13 +239,13 @@
 
     replaceTool <- toolItemNew
     rentry <- entryNew
-    widgetSetName rentry "replaceEntry"
+    widgetSetName rentry ("replaceEntry" :: Text)
     containerAdd replaceTool rentry
-    widgetSetName replaceTool "replaceTool"
+    widgetSetName replaceTool ("replaceTool" :: Text)
     toolbarInsert toolbar replaceTool 0
 
     labelTool2 <- toolItemNew
-    label2 <- labelNew (Just "Replace: ")
+    label2 <- labelNew (Just (__"Replace: "))
     containerAdd labelTool2 label2
     toolbarInsert toolbar labelTool2 0
 
@@ -248,30 +254,31 @@
 
     nextButton <- toolButtonNewFromStock "gtk-go-forward"
     toolbarInsert toolbar nextButton 0
-    set nextButton [widgetTooltipText := Just "Search for the next match in the current file"]
+    set nextButton [widgetTooltipText := Just (__"Search for the next match in the current file")]
     nextButton `onToolButtonClicked` doSearch toolbar Forward ideR
 
     wrapAroundButton <- toggleToolButtonNew
-    toolButtonSetLabel wrapAroundButton (Just "Wrap")
-    widgetSetName wrapAroundButton "wrapAroundButton"
+    toolButtonSetLabel wrapAroundButton (Just (__"Wrap"))
+    widgetSetName wrapAroundButton ("wrapAroundButton" :: Text)
     toolbarInsert toolbar wrapAroundButton 0
-    set wrapAroundButton [widgetTooltipText := Just "When selected searching will continue from the top when no more matches are found"]
+    set wrapAroundButton [widgetTooltipText := Just (__"When selected searching will continue from the top when no more matches are found")]
 
     previousButton <- toolButtonNewFromStock "gtk-go-back"
     toolbarInsert toolbar previousButton 0
-    set previousButton [widgetTooltipText := Just "Search for the previous match in the current file"]
+    set previousButton [widgetTooltipText := Just (__"Search for the previous match in the current file")]
     previousButton `onToolButtonClicked` doSearch toolbar Backward ideR
 
     entryTool <- toolItemNew
     entry <- entryNew
-    widgetSetName entry "searchEntry"
+    widgetSetName entry ("searchEntry" :: Text)
     containerAdd entryTool entry
-    widgetSetName entryTool "searchEntryTool"
+    widgetSetName entryTool ("searchEntryTool" :: Text)
     toolItemSetExpand entryTool True
     toolbarInsert toolbar entryTool 0
 
+    let column0 = makeColumnIdString 0
     store <- listStoreNew []
-    customStoreSetColumn store (makeColumnIdString 0) id
+    customStoreSetColumn store column0 id
 
     completion <- entryCompletionNew
     entrySetCompletion entry completion
@@ -283,39 +290,39 @@
         (\ cd -> [cellText := cd])
     entryCompletionSetMatchFunc completion (matchFunc store)
     on completion matchSelected $ \ model iter -> do
-        txt <- treeModelGetValue model iter (makeColumnIdString 0)
+        txt <- treeModelGetValue model iter column0
         entrySetText entry txt
         doSearch toolbar Forward ideR
         return True
 
     regexButton <- toggleToolButtonNew
-    toolButtonSetLabel regexButton (Just "Regex")
-    widgetSetName regexButton "regexButton"
+    toolButtonSetLabel regexButton (Just (__"Regex"))
+    widgetSetName regexButton ("regexButton" :: Text)
     toolbarInsert toolbar regexButton 0
     regexButton `onToolButtonClicked` doSearch toolbar Insert ideR
-    set regexButton [widgetTooltipText := Just "When selected the search string is used as a regular expression"]
+    set regexButton [widgetTooltipText := Just (__"When selected the search string is used as a regular expression")]
 
     entireWordButton <- toggleToolButtonNew
-    toolButtonSetLabel entireWordButton (Just "Words")
-    widgetSetName entireWordButton "entireWordButton"
+    toolButtonSetLabel entireWordButton (Just (__"Words"))
+    widgetSetName entireWordButton ("entireWordButton" :: Text)
     toolbarInsert toolbar entireWordButton 0
     entireWordButton `onToolButtonClicked` doSearch toolbar Insert ideR
-    set entireWordButton [widgetTooltipText := Just "When selected only entire words are matched"]
+    set entireWordButton [widgetTooltipText := Just (__"When selected only entire words are matched")]
 
     caseSensitiveButton <- toggleToolButtonNew
-    toolButtonSetLabel caseSensitiveButton (Just "Case")
-    widgetSetName caseSensitiveButton "caseSensitiveButton"
+    toolButtonSetLabel caseSensitiveButton (Just (__"Case"))
+    widgetSetName caseSensitiveButton ("caseSensitiveButton" :: Text)
     toolbarInsert toolbar caseSensitiveButton 0
     caseSensitiveButton `onToolButtonClicked`
        doSearch toolbar Insert ideR
-    set caseSensitiveButton [widgetTooltipText := Just "When selected the search is case sensitive"]
+    set caseSensitiveButton [widgetTooltipText := Just (__"When selected the search is case sensitive")]
 
     labelTool <- toolItemNew
-    label <- labelNew (Just "Find: ")
+    label <- labelNew (Just (__"Find: "))
     containerAdd labelTool label
     toolbarInsert toolbar labelTool 0
 
-    after entry insertText (\ t i -> do
+    after entry insertText (\ (t::Text) i -> do
         doSearch toolbar Insert ideR
         return i)
     after entry deleteText (\ _ _ -> doSearch toolbar Delete ideR)
@@ -352,7 +359,7 @@
                 widgetGrabFocus re
                 --- widgetAc
                 return True
-            _ | mapControlCommand Control `elem` mods -> liftIO . ctrl $ map toLower name
+            _ | mapControlCommand Control `elem` mods -> liftIO . ctrl $ T.toLower name
             _        -> return False
 
     rentry `on` keyPressEvent $ do
@@ -364,7 +371,7 @@
                     widgetGrabFocus fe
                     return True
              | mapControlCommand Control `elem` mods ->
-                        liftIO . ctrl $ map toLower name
+                        liftIO . ctrl $ T.toLower name
              | otherwise -> return False
 
     after spinL focusInEvent . liftIO $ reflectIDE (inActiveBufContext True $ \ _ _ ebuf _ _ -> do
@@ -381,7 +388,7 @@
                 re <- getFindEntry toolbar
                 widgetGrabFocus re
                 return True
-            _ | mapControlCommand Control `elem` mods -> liftIO . ctrl $ map toLower name
+            _ | mapControlCommand Control `elem` mods -> liftIO . ctrl $ T.toLower name
             _ -> return False
 
     after spinL entryActivate $ reflectIDE (inActiveBufContext () $ \ _ sv ebuf _ _ -> do
@@ -424,7 +431,7 @@
     case mbExpAndMatchIndex of
         Just (exp, matchIndex) -> do
             res           <- reflectIDE (editFind entireWord caseSensitive wrapAround regex search "" hint) ideR
-            if res || null search
+            if res || T.null search
                 then do
                     widgetModifyBase entry StateNormal white
                     widgetModifyText entry StateNormal black
@@ -432,7 +439,7 @@
                     widgetModifyBase entry StateNormal red
                     widgetModifyText entry StateNormal white
         Nothing ->
-            if null search
+            if T.null search
                 then do
                     widgetModifyBase entry StateNormal white
                     widgetModifyText entry StateNormal black
@@ -455,24 +462,24 @@
     let (regexString, _) = regexStringAndMatchIndex entireWord regex search
     liftIDE $ workspaceTry $ grepWorkspace regexString caseSensitive
 
-matchFunc :: ListStore String -> String -> TreeIter -> IO Bool
+matchFunc :: ListStore Text -> Text -> TreeIter -> IO Bool
 matchFunc model str iter = do
   tp <- treeModelGetPath model iter
   case tp of
          (i:_) -> do row <- listStoreGetValue model i
-                     return (isPrefixOf (map toLower str) (map toLower row) && length str < length row)
+                     return (T.isPrefixOf (T.toLower str) (T.toLower row) && T.length str < T.length row)
          otherwise -> return False
 
-addToHist :: String -> IDEAction
+addToHist :: Text -> IDEAction
 addToHist str =
-    unless (null str) $
+    unless (T.null str) $
        do (_, ls) <- needFindbar
           liftIO $
             do entryHist <- listStoreToList ls
-               unless (any (str `isPrefixOf`) entryHist) $
+               unless (any (str `T.isPrefixOf`) entryHist) $
                  do let newList
                           = take 12
-                              (str : filter (\ e -> not (e `isPrefixOf` str)) entryHist)
+                              (str : filter (\ e -> not (e `T.isPrefixOf` str)) entryHist)
                     listStoreClear ls
                     mapM_ (listStoreAppend ls) newList
 
@@ -505,14 +512,14 @@
                 ideR
     return ()
 
-editFind :: Bool -> Bool -> Bool -> Bool -> String -> String -> SearchHint -> IDEM Bool
+editFind :: Bool -> Bool -> Bool -> Bool -> Text -> Text -> SearchHint -> IDEM Bool
 editFind entireWord caseSensitive wrapAround regex search dummy hint = do
     mbExpAndMatchIndex <- liftIO $ regexAndMatchIndex caseSensitive entireWord regex search
     case mbExpAndMatchIndex of
         Nothing -> return False
         Just (exp, matchIndex) -> editFind' exp matchIndex wrapAround dummy hint
 
-editFind' :: Regex -> Int -> Bool -> String -> SearchHint -> IDEM Bool
+editFind' :: Regex -> Int -> Bool -> Text -> SearchHint -> IDEM Bool
 editFind' exp matchIndex wrapAround dummy hint =
     inActiveBufContext False $ \_ sv ebuf _ _ -> do
     i1 <- getStartIter ebuf
@@ -561,30 +568,30 @@
             offset <- getOffset iter
             findMatch exp matchIndex ebuf text (>= offset) False
 
-regexAndMatchIndex :: Bool -> Bool -> Bool -> String -> IO (Maybe (Regex, Int))
+regexAndMatchIndex :: Bool -> Bool -> Bool -> Text -> IO (Maybe (Regex, Int))
 regexAndMatchIndex caseSensitive entireWord regex string =
-    if null string
+    if T.null string
         then return Nothing
         else do
             let (regexString, index) = regexStringAndMatchIndex entireWord regex string
             case compileRegex caseSensitive regexString of
                 Left err -> do
-                    sysMessage Normal err
+                    sysMessage Normal $ T.pack err
                     return Nothing
                 Right regex -> return $ Just (regex, index)
 
-regexStringAndMatchIndex :: Bool -> Bool -> String -> (String, Int)
+regexStringAndMatchIndex :: Bool -> Bool -> Text -> (Text, Int)
 regexStringAndMatchIndex entireWord regex string =
     -- Escape non regex string
     let regexString = if regex
                         then string
-                        else foldl (\s c -> s ++ if isAlphaNum c then [c] else ['\\', c]) "" string in
+                        else foldl (\s c -> s <> if isAlphaNum c then T.singleton c else "\\"<>T.singleton c) "" $ T.unpack string in
     -- Regular expression with word filter if needed
     if entireWord
-        then ("(^|[^a-zA-Z0-9])(" ++ regexString ++ ")($|[^a-zA-Z0-9])", 2)
+        then ("(^|[^a-zA-Z0-9])(" <> regexString <> ")($|[^a-zA-Z0-9])", 2)
         else (regexString, 0)
 
-findMatch :: TextEditor editor => Regex -> Int -> EditorBuffer editor -> String -> (Int -> Bool) -> Bool -> IDEM (Maybe (EditorIter editor, EditorIter editor, MatchArray))
+findMatch :: TextEditor editor => Regex -> Int -> EditorBuffer editor -> Text -> (Int -> Bool) -> Bool -> IDEM (Maybe (EditorIter editor, EditorIter editor, MatchArray))
 findMatch exp matchIndex gtkbuf text offsetPred findLast = do
     let matches = (if findLast then reverse else id) (matchAll exp text)
     case find (offsetPred . fst . (!matchIndex)) matches of
@@ -595,11 +602,11 @@
             return $ Just (iter1, iter2, matches)
         Nothing -> return Nothing
 
-editReplace :: Bool -> Bool -> Bool -> Bool -> String -> String -> SearchHint -> IDEM Bool
+editReplace :: Bool -> Bool -> Bool -> Bool -> Text -> Text -> SearchHint -> IDEM Bool
 editReplace entireWord caseSensitive wrapAround regex search replace hint =
     editReplace' entireWord caseSensitive wrapAround regex search replace hint True
 
-editReplace' :: Bool -> Bool -> Bool -> Bool -> String -> String -> SearchHint -> Bool -> IDEM Bool
+editReplace' :: Bool -> Bool -> Bool -> Bool -> Text -> Text -> SearchHint -> Bool -> IDEM Bool
 editReplace' entireWord caseSensitive wrapAround regex search replace hint mayRepeat =
     inActiveBufContext False $ \_ _ ebuf _ _ -> do
         insertMark <- getInsertMark ebuf
@@ -614,11 +621,11 @@
                 match  <- findMatch exp matchIndex ebuf text (== offset) False
                 case match of
                     Just (iterStart, iterEnd, matches) -> do
-                        mbText <- liftIO $ replacementText regex text matchIndex matches replace
+                        mbText <- liftIO $ replacementText regex text matchIndex matches $ T.unpack replace
                         case mbText of
                             Just text -> do
                                 delete ebuf iterStart iterEnd
-                                insert ebuf iterStart text
+                                insert ebuf iterStart (T.pack text)
                             Nothing -> do
                                 sysMessage Normal
                                     "Should never happen. findMatch worked but repleacementText failed"
@@ -636,11 +643,11 @@
         replacementText True text matchIndex matches replace =
             case compileRegex caseSensitive search of
                 Left err -> do
-                    sysMessage Normal err
+                    sysMessage Normal $ T.pack err
                     return Nothing
                 Right exp -> return $ Just $ regexReplacement text matchIndex matches replace
 
-regexReplacement :: String -> Int -> MatchArray -> String -> String
+regexReplacement :: Text -> Int -> MatchArray -> String -> String
 regexReplacement _ _ _ [] = []
 regexReplacement text matchIndex matches ('\\' : '\\' : xs) = '\\' : regexReplacement text matchIndex matches xs
 regexReplacement text matchIndex matches ('\\' : n : xs) | isDigit n =
@@ -648,20 +655,20 @@
         value    = if inRange (bounds matches) subIndex
                     then
                         let subExp = matches!(matchIndex + digitToInt n) in
-                        take (snd subExp) $ drop (fst subExp) text
+                        take (snd subExp) $ drop (fst subExp) $ T.unpack text
                     else ['\\', n] in
     value ++ regexReplacement text matchIndex matches xs
 
 regexReplacement text matchIndex matches (x : xs) = x : regexReplacement text matchIndex matches xs
 
-editReplaceAll :: Bool -> Bool -> Bool -> Bool -> String -> String -> SearchHint -> IDEM Bool
+editReplaceAll :: Bool -> Bool -> Bool -> Bool -> Text -> Text -> SearchHint -> IDEM Bool
 editReplaceAll entireWord caseSensitive wrapAround regex search replace hint = do
     res <- editReplace' entireWord caseSensitive False regex search replace hint True
     if res
         then editReplaceAll entireWord caseSensitive False regex search replace hint
         else return False
 
-compileRegex :: Bool -> String -> Either String Regex
+compileRegex :: Bool -> Text -> Either String Regex
 compileRegex caseSense searchString =
     let compOption = defaultCompOpt {
                             Regex.caseSensitive = caseSense
@@ -673,7 +680,7 @@
 white = Color 64000 64000 64000
 black = Color 0 0 0
 
-needFindbar :: IDEM (Toolbar,ListStore String)
+needFindbar :: IDEM (Toolbar,ListStore Text)
 needFindbar = do
     (_,mbfb) <- readIDE findbar
     case mbfb of
@@ -715,7 +722,7 @@
 getReplaceEntry = getWidget "replaceTool"
 getFindEntry    = getWidget "searchEntryTool"
 
-getWidget :: String -> Toolbar -> IO Widget
+getWidget :: Text -> Toolbar -> IO Widget
 getWidget str tb = do
     widgets <- containerGetChildren tb
     entryL <-  filterM (liftM (== str) . widgetGetName) widgets
@@ -733,7 +740,7 @@
 getCaseSensitive = getSelection "caseSensitiveButton"
 getRegex         = getSelection "regexButton"
 
-getSelection :: String -> Toolbar -> IO Bool
+getSelection :: Text -> Toolbar -> IO Bool
 getSelection str tb = do
     widgets <- containerGetChildren tb
     entryL <-  filterM (liftM (== str) . widgetGetName) widgets
@@ -747,7 +754,7 @@
 setCaseSensitive = setSelection "caseSensitiveButton"
 setRegex         = setSelection "regexButton"
 
-setSelection :: String -> Toolbar -> Bool ->  IO ()
+setSelection :: Text -> Toolbar -> Bool ->  IO ()
 setSelection str tb bool = do
     widgets <- containerGetChildren tb
     entryL <-  filterM (liftM (== str) . widgetGetName ) widgets
diff --git a/src/IDE/ImportTool.hs b/src/IDE/ImportTool.hs
--- a/src/IDE/ImportTool.hs
+++ b/src/IDE/ImportTool.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.ImportTool
@@ -29,6 +30,7 @@
 import Distribution.Text (simpleParse, display, disp)
 import IDE.Pane.SourceBuffer
 import Graphics.UI.Gtk
+import IDE.Utils.GUIUtils
 import Text.ParserCombinators.Parsec.Language (haskellStyle)
 import Graphics.UI.Editor.MakeEditor
        (getRealWidget, FieldDescription(..), buildEditor, mkField)
@@ -66,11 +68,15 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import Distribution.PackageDescription.PrettyPrint
        (writeGenericPackageDescription)
-import qualified Data.Text as T (unpack)
+import qualified Data.Text as T
+       (takeWhile, stripPrefix, lines, dropWhile, empty, length, take,
+        pack, unpack)
 import Language.Haskell.Exts (KnownExtension)
+import Data.Text (Text)
+import Data.Monoid ((<>))
 
-readMaybe :: Read a => String -> Maybe a
-readMaybe s = case reads s of
+readMaybe :: Read a => Text -> Maybe a
+readMaybe s = case reads $ T.unpack s of
                 [(x, "")] -> Just x
                 _         -> Nothing
 
@@ -85,11 +91,11 @@
     addPackageResults <- forM errors addPackage
     let notInScopes = [ y | (x,y) <-
             nubBy (\ (p1,_) (p2,_) -> p1 == p2)
-                $ [(x,y) |  (x,y) <- [((parseNotInScope . T.unpack . refDescription) e, e) | e <- errors]],
+                $ [(x,y) |  (x,y) <- [((parseNotInScope . refDescription) e, e) | e <- errors]],
                                 isJust x]
     let extensions = [ y | (x,y) <-
             nubBy (\ (p1,_) (p2,_) -> p1 == p2)
-                $ [(x,y) |  (x,y) <- [((parsePerhapsYouIntendedToUse . T.unpack . refDescription) e, e) | e <- errors]],
+                $ [(x,y) |  (x,y) <- [((parsePerhapsYouIntendedToUse . refDescription) e, e) | e <- errors]],
                                 length x == 1]
     when (not (or addPackageResults) && null notInScopes && null extensions) $ ideMessage Normal $ "No errors that can be auto resolved"
     addAll buildInBackground notInScopes extensions
@@ -125,7 +131,7 @@
 -- be used for default selection
 addImport :: LogRef -> [Descr] -> ((Bool,[Descr]) -> IDEAction) -> IDEAction
 addImport error descrList continuation =
-    case parseNotInScope . T.unpack $ refDescription error of
+    case parseNotInScope $ refDescription error of
         Nothing -> continuation (True,descrList)
         Just nis -> do
             currentInfo' <- getScopeForActiveBuffer
@@ -139,7 +145,7 @@
                         wslist = getIdentifierDescr (id' nis) symbolTable3 symbolTable4
                     in case (list, wslist) of
                         ([], []) ->  do
-                            ideMessage Normal $ "Identifier " ++ (id' nis) ++ " not found"
+                            ideMessage Normal $ "Identifier " <> (id' nis) <> " not found"
                             continuation (True, descrList)
                         ([], list) -> do
                             window' <- getMainWindow
@@ -170,12 +176,12 @@
 
 addPackage :: LogRef -> IDEM Bool
 addPackage error = do
-    case parseHiddenModule . T.unpack $ refDescription error of
+    case parseHiddenModule $ refDescription error of
         Nothing -> return False
         Just (HiddenModuleResult mod pack) -> do
             let idePackage = logRefPackage error
             gpd <- liftIO $ readPackageDescription normal (ipdCabalFile $ idePackage)
-            ideMessage Normal $ "addPackage " ++ (display $ pkgName pack)
+            ideMessage Normal $ "addPackage " <> (T.pack . display $ pkgName pack)
             liftIO $ writeGenericPackageDescription (ipdCabalFile $ idePackage)
                 gpd { condLibrary     = addDepToLib pack (condLibrary gpd),
                       condExecutables = map (addDepToExe pack)
@@ -218,13 +224,13 @@
     case (mbBuf,mbMod) of
         (Just buf,Just mod) -> do
             inActiveBufContext () $ \ nb _ gtkbuf idebuf n -> do
-                ideMessage Normal $ "addImport " ++ show (dscName descr) ++ " from "
-                    ++ (render $ disp $ mod)
+                ideMessage Normal $ "addImport " <> T.pack (show $ dscName descr) <> " from "
+                    <> T.pack (render $ disp mod)
                 doServerCommand (ParseHeaderCommand filePath)  $ \ res ->
                     case res of
                          ServerHeader (Left imports) ->
                             case filter (qualifyAsImportStatement mod) imports of
-                                []     ->   let newLine  =  prettyPrint (newImpDecl mod) ++ "\n"
+                                []     ->   let newLine  =  prettyPrint (newImpDecl mod) <> "\n"
                                                 lastLine = foldr max 0 (map (locationELine . importLoc) imports)
                                             in do
                                                 i1 <- getIterAtLine gtkbuf lastLine
@@ -234,7 +240,7 @@
                                                 continuation (True,(descr : descrList))
                                 l@(impDecl:_) ->
                                                 let newDecl     =  addToDecl impDecl
-                                                    newLine     =  prettyPrint newDecl ++ "\n"
+                                                    newLine     =  prettyPrint newDecl <> "\n"
                                                     myLoc       =  importLoc impDecl
                                                     lineStart   =  locationSLine myLoc
                                                     lineEnd     =  locationELine myLoc
@@ -247,7 +253,7 @@
                                                     setModified gtkbuf True
                                                     continuation (True,(descr : descrList))
                          ServerHeader (Right lastLine) ->
-                                            let newLine  =  prettyPrint (newImpDecl mod) ++ "\n"
+                                            let newLine  =  prettyPrint (newImpDecl mod) <> "\n"
                                             in do
                                                 i1 <- getIterAtLine gtkbuf lastLine
                                                 editInsertCode gtkbuf i1 newLine
@@ -255,8 +261,8 @@
                                                 setModified gtkbuf True
                                                 continuation (True,(descr : descrList))
                          ServerFailed string -> do
-                            ideMessage Normal ("Can't parse module header " ++ filePath ++
-                                    " failed with: " ++ string)
+                            ideMessage Normal ("Can't parse module header " <> T.pack filePath <>
+                                    " failed with: " <> string)
                             continuation (False,[])
                          _ ->    do
                             ideMessage Normal ("ImportTool>>addImport: Impossible server answer")
@@ -267,7 +273,7 @@
         qualifyAsImportStatement moduleName impDecl =
             let importName = importModule impDecl
                 getHiding (ImportSpecList isHiding _) = isHiding
-            in importName == display moduleName
+            in importName == T.pack (display moduleName)
                 && ((isNothing (mbQual' nis) &&  not (importQualified impDecl)) ||
                     (isJust (mbQual' nis) && importQualified impDecl
                         && fromJust (mbQual' nis) == qualString impDecl))
@@ -275,7 +281,7 @@
         newImpDecl :: D.ModuleName -> ImportDecl
         newImpDecl mod = ImportDecl {
                         importLoc       = noLocation,
-                        importModule    = display mod,
+                        importModule    = T.pack $ display mod,
                         importQualified = isJust (mbQual' nis),
                         importSrc       = False,
                         importPkg       = Nothing,
@@ -292,7 +298,7 @@
                                     impDecl{importSpecs = Just (ImportSpecList False (nub (newImportSpec : listIE)))}
                                 Nothing             ->
                                     impDecl{importSpecs = Just (ImportSpecList False [newImportSpec])}
-        noLocation  = Location 0 0 0 0
+        noLocation  = Location "" 0 0 0 0
 
 getRealId descr id = case descr of
     Reexported rdescr -> getRealId (dsrDescr rdescr) id
@@ -303,7 +309,7 @@
         getReal (MethodDescr d) = IThingAll (dscName d)
         getReal _ = IVar id
 
-qualString ::  ImportDecl -> String
+qualString ::  ImportDecl -> Text
 qualString impDecl = case importAs impDecl of
                         Nothing -> ""
                         Just modName -> modName
@@ -311,8 +317,8 @@
 -- | The import data
 
 data NotInScopeParseResult = NotInScopeParseResult {
-        mbQual' ::   Maybe String
-    ,   id'     ::   String
+        mbQual' ::   Maybe Text
+    ,   id'     ::   Text
     ,   isSub'  ::   Bool
     ,   isOp'   ::   Bool}
     deriving Eq
@@ -321,15 +327,15 @@
 
 lexer      = P.makeTokenParser haskellStyle
 whiteSpace = P.whiteSpace lexer
-lexeme     = P.lexeme lexer
+lexeme     = (T.pack <$>) . P.lexeme lexer
 symbol     = P.symbol lexer
-identifier = P.identifier lexer
+identifier = T.pack <$> P.identifier lexer
 dot        = P.dot lexer
-operator   = P.operator lexer
+operator   = T.pack <$> P.operator lexer
 
-parseNotInScope :: String -> (Maybe NotInScopeParseResult)
+parseNotInScope :: Text -> (Maybe NotInScopeParseResult)
 parseNotInScope str =
-    case Parsec.parse scopeParser "" str of
+    case Parsec.parse scopeParser "" $ T.unpack str of
         Left e   -> Nothing
         Right r  -> Just r
 
@@ -348,7 +354,7 @@
             id     <- optionMaybe (try identifier)
             case id of
                 Just id -> return (NotInScopeParseResult mbQual
-                                (take (length id - 1) id)  (isJust isSub) False)
+                                (T.take (T.length id - 1) id)  (isJust isSub) False)
                 Nothing -> do
                     op <-   operator
                     char '\''
@@ -379,10 +385,10 @@
 
 -- |* The little dialog to choose between possible modules
 
-moduleFields :: [String] -> String -> FieldDescription String
+moduleFields :: [Text] -> Text -> FieldDescription Text
 moduleFields list ident =
         mkField
-            (paraName <<<- ParaName ("From which module is " ++ ident)
+            (paraName <<<- ParaName ("From which module is " <> ident)
                 $ paraMultiSel <<<- ParaMultiSel False
                     $ paraMinSize <<<- ParaMinSize (300,400)
                         $ emptyParams)
@@ -390,9 +396,9 @@
             (\ a b -> a)
             (staticListEditor ( list) id)
 
-selectModuleDialog :: Window -> [Descr] -> String -> Maybe String -> Maybe Descr -> IO (Maybe Descr)
+selectModuleDialog :: Window -> [Descr] -> Text -> Maybe Text -> Maybe Descr -> IO (Maybe Descr)
 selectModuleDialog parentWindow list id mbQual mbDescr =
-    let selectionList       =  (nub . sort) $ map (render . disp . modu . fromJust . dsMbModu) list
+    let selectionList       =  (nub . sort) $ map (T.pack . render . disp . modu . fromJust . dsMbModu) list
     in if length selectionList == 1
         then return (Just (head list))
         else do
@@ -400,7 +406,7 @@
                                             Nothing -> Nothing
                                             Just descr -> case dsMbModu descr of
                                                             Nothing -> Nothing
-                                                            Just pm -> Just ((render . disp . modu) pm)
+                                                            Just pm -> Just ((T.pack . render . disp . modu) pm)
             let realSelectionString =  case mbSelectedString of
                                             Nothing -> head selectionList
                                             Just str -> if elem str selectionList
@@ -408,7 +414,7 @@
                                                             else head selectionList
             let qualId             =  case mbQual of
                                             Nothing -> id
-                                            Just str -> str ++ "." ++ id
+                                            Just str -> str <> "." <> id
             dia               <- dialogNew
             set dia [ windowTransientFor := parentWindow ]
 #ifdef MIN_VERSION_gtk3
@@ -416,8 +422,8 @@
 #else
             upper             <- dialogGetUpper dia
 #endif
-            okButton <- dialogAddButton dia "Ok" ResponseOk
-            dialogAddButton dia "Cancel" ResponseCancel
+            okButton <- dialogAddButton dia (__"Add Import") ResponseOk
+            dialogAddButton dia (__"Cancel") ResponseCancel
             (widget,inj,ext,_) <- buildEditor (moduleFields selectionList qualId) realSelectionString
             boxPackStart (castToBox upper) widget PackGrow 7
             dialogSetDefaultResponse dia ResponseOk --does not work for the tree view
@@ -426,7 +432,7 @@
             set okButton [widgetCanDefault := True]
             widgetGrabDefault okButton
             resp <- dialogRun dia
-            value                      <- ext ([])
+            value                      <- ext (T.empty)
             widgetHide dia
             widgetDestroy dia
             --find
@@ -434,35 +440,35 @@
                 (ResponseOk,Just v)    -> return (Just (head
                                             (filter (\e -> case dsMbModu e of
                                                 Nothing -> False
-                                                Just pm -> (render . disp . modu) pm == v) list)))
+                                                Just pm -> (T.pack . render . disp . modu) pm == v) list)))
                 _                      -> return Nothing
 
 data HiddenModuleResult = HiddenModuleResult {
-        hiddenModule      :: String
+        hiddenModule      :: Text
     ,   missingPackage    :: PackageId}
     deriving (Eq, Show)
 
-parseHiddenModule :: String -> (Maybe HiddenModuleResult)
+parseHiddenModule :: Text -> (Maybe HiddenModuleResult)
 parseHiddenModule str =
-    case Parsec.parse hiddenModuleParser "" str of
+    case Parsec.parse hiddenModuleParser "" $ T.unpack str of
         Left e             -> Nothing
         Right (mod, pack)  ->
-            case simpleParse pack of
+            case simpleParse $ T.unpack pack of
                 Just p  -> Just $ HiddenModuleResult mod p
                 Nothing -> Nothing
 
-hiddenModuleParser :: CharParser () (String, String)
+hiddenModuleParser :: CharParser () (Text, Text)
 hiddenModuleParser = do
     whiteSpace
     symbol "Could not find module "
     (char '`' <|> char '‛' <|> char '‘')
-    mod    <- many (noneOf "'’")
+    mod    <- T.pack <$> many (noneOf "'’")
     many (noneOf "\n")
     symbol "\n"
     whiteSpace
     symbol "It is a member of the hidden package "
     (char '`' <|> char '‛' <|> char '‘')
-    pack   <- many (noneOf "'’")
+    pack   <- T.pack <$> many (noneOf "'’")
     (char '\'' <|> char '’')
     symbol ".\n"
     many anyChar
@@ -477,50 +483,50 @@
 -- > parsePerhapsExt "Error blah blah\n   Perhaps you intended to use ScopedTypeVariables\n\n"
 --
 -- > parsePerhapsExt "Error blah blah\n   Use -XNoBugsExt\n\n"
-parsePerhapsYouIntendedToUse :: String -> [KnownExtension]
+parsePerhapsYouIntendedToUse :: Text -> [KnownExtension]
 parsePerhapsYouIntendedToUse =
-    concatMap (parseLine . dropWhile (==' ')) . lines
+    concatMap (parseLine . T.dropWhile (==' ')) . T.lines
   where
-    parseLine :: String -> [KnownExtension]
+    parseLine :: Text -> [KnownExtension]
     parseLine line = take 1 . catMaybes . map readMaybe $ catMaybes [
-        stripPrefix "Perhaps you intended to use -X" line
-      , stripPrefix "Perhaps you intended to use " line
-      , takeWhile (/=' ') <$> stripPrefix "Use -X" line
-      , takeWhile (/=' ') <$> stripPrefix "Use " line
-      , takeWhile (/=' ') <$> stripPrefix "(Use -X" line
-      , takeWhile (/=' ') <$> stripPrefix "(Use " line
-      , takeWhile (/=' ') <$> stripPrefix "You need -X" line
-      , takeWhile (/=' ') <$> stripPrefix "You need " line]
+        T.stripPrefix "Perhaps you intended to use -X" line
+      , T.stripPrefix "Perhaps you intended to use " line
+      , T.takeWhile (/=' ') <$> T.stripPrefix "Use -X" line
+      , T.takeWhile (/=' ') <$> T.stripPrefix "Use " line
+      , T.takeWhile (/=' ') <$> T.stripPrefix "(Use -X" line
+      , T.takeWhile (/=' ') <$> T.stripPrefix "(Use " line
+      , T.takeWhile (/=' ') <$> T.stripPrefix "You need -X" line
+      , T.takeWhile (/=' ') <$> T.stripPrefix "You need " line]
 
 addExtension :: LogRef -> (Bool -> IDEAction) -> IDEAction
 addExtension error continuation =
-    case parsePerhapsYouIntendedToUse . T.unpack $ refDescription error of
+    case parsePerhapsYouIntendedToUse $ refDescription error of
         []    -> continuation True
-        [ext] -> addExtension' (show ext) (logRefFullFilePath error) continuation
+        [ext] -> addExtension' (T.pack $ show ext) (logRefFullFilePath error) continuation
         list  -> continuation True
 
-addExtension' :: String -> FilePath -> (Bool -> IDEAction) -> IDEAction
+addExtension' :: Text -> FilePath -> (Bool -> IDEAction) -> IDEAction
 addExtension' ext filePath continuation =  do
     mbBuf  <- selectSourceBuf filePath
     case mbBuf of
         Just buf ->
             inActiveBufContext () $ \ nb _ gtkbuf idebuf n -> do
-                ideMessage Normal $ "addExtension " ++ ext
+                ideMessage Normal $ "addExtension " <> ext
                 i1 <- getIterAtLine gtkbuf 0
-                editInsertCode gtkbuf i1 $ "{-# LANGUAGE " ++ ext ++ " #-}\n"
+                editInsertCode gtkbuf i1 $ "{-# LANGUAGE " <> ext <> " #-}\n"
                 fileSave False
                 setModified gtkbuf True
                 continuation True
         _  -> return ()
 
 addResolveMenuItems ideR theMenu logRef = do
-    let msg = T.unpack $ refDescription logRef
+    let msg = refDescription logRef
     when (isJust $ parseNotInScope msg) $
-        addFixMenuItem "Add Import"  $ addImport logRef [] (\ _ -> return ())
+        addFixMenuItem (__"Add Import")  $ addImport logRef [] (\ _ -> return ())
     when (isJust $ parseHiddenModule msg) $
-        addFixMenuItem "Add Package" $ addPackage logRef
+        addFixMenuItem (__"Add Package") $ addPackage logRef
     when ((length $ parsePerhapsYouIntendedToUse msg) == 1) $
-        addFixMenuItem "Add Extension" $ addExtension logRef (\ _ -> return ())
+        addFixMenuItem (__"Add Extension") $ addExtension logRef (\ _ -> return ())
   where
     addFixMenuItem name fix = do
         item <- menuItemNewWithLabel name
diff --git a/src/IDE/Keymap.hs b/src/IDE/Keymap.hs
--- a/src/IDE/Keymap.hs
+++ b/src/IDE/Keymap.hs
@@ -19,6 +19,9 @@
 import IDE.Core.State
 import Control.Monad (foldM)
 import System.Log.Logger (infoM)
+import Data.Text (Text)
+import qualified Data.Text as T (toLower, unpack, pack)
+import Control.Applicative ((<$>))
 
 class Keymap alpha where
     parseKeymap         ::   FilePath -> IO alpha
@@ -40,7 +43,7 @@
     infoM "leksah" $ "Reading keymap from " ++ fn
     res <- parseFromFile keymapParser fn
     case res of
-        Left pe -> throwIDE $"Error reading keymap file " ++ show fn ++ " " ++ show pe
+        Left pe -> throwIDE . T.pack $ "Error reading keymap file " ++ show fn ++ " " ++ show pe
         Right r -> return r
 
 --
@@ -94,10 +97,10 @@
                 }
 lexer = P.makeTokenParser keymapStyle
 lexeme = P.lexeme lexer
-identifier = P.identifier lexer
+identifier = T.pack <$> P.identifier lexer
 symbol =  P.symbol lexer
 whiteSpace = P.whiteSpace lexer
-stringLiteral = P.stringLiteral lexer
+stringLiteral = T.pack <$> P.stringLiteral lexer
 
 keymapParser :: CharParser () KeymapI
 keymapParser = do
@@ -107,7 +110,7 @@
     return (KM (Map.fromListWith (++) ls))
 
 lineparser :: CharParser () (ActionString, [(Maybe (Either KeyString
-                                (KeyString,KeyString)), Maybe String)])
+                                (KeyString,KeyString)), Maybe Text)])
 lineparser = do
     mb1 <- option Nothing (do
         keyDescr <- identifier
@@ -132,12 +135,12 @@
 --------------------------------------------------
 -- Have to write this until gtk_accelerator_parse gets bound in gtk2hs
 --
-accParse :: String -> IO (KeyVal,[Modifier])
-accParse str = case parse accparser "accelerator" str of
+accParse :: Text -> IO (KeyVal,[Modifier])
+accParse str = case parse accparser "accelerator" (T.unpack str) of
     Right (ks,mods) -> do
-        key <- keyvalFromName (map toLower ks)
+        key <- keyvalFromName $ T.toLower ks
         return (key,sort mods)
-    Left e -> throwIDE $show e
+    Left e -> throwIDE . T.pack $ show e
 
 accStyle :: P.LanguageDef st
 accStyle= emptyDef{P.caseSensitive = False}
@@ -145,15 +148,15 @@
 lexer2 = P.makeTokenParser accStyle
 lexeme2 = P.lexeme lexer2
 symbol2 =  P.symbol lexer2
-identifier2 =  P.identifier lexer2
+identifier2 = T.pack <$> P.identifier lexer2
 whiteSpace2 = P.whiteSpace lexer2
 
-accparser :: GenParser Char () (String,[Modifier])
+accparser :: GenParser Char () (Text,[Modifier])
 accparser = do
     whiteSpace2
     mods <- many modparser
     key <- identifier2
-    return (key,mods)
+    return (key, mods)
 
 modparser :: GenParser Char () Modifier
 modparser = do
diff --git a/src/IDE/Leksah.hs b/src/IDE/Leksah.hs
--- a/src/IDE/Leksah.hs
+++ b/src/IDE/Leksah.hs
@@ -52,7 +52,7 @@
 import IDE.Find
 import Graphics.UI.Editor.Composite (filesEditor, maybeEditor)
 import Graphics.UI.Editor.Simple
-       (enumEditor, stringEditor)
+       (stringEditor, enumEditor, textEditor)
 import IDE.Metainfo.Provider (initInfo)
 import IDE.Workspaces
        (workspaceAddPackage', workspaceTryQuiet, workspaceNewHere,
@@ -78,13 +78,15 @@
 import Control.Monad (when, unless, liftM)
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Applicative ((<$>))
-import qualified Data.Text as T (unpack, stripPrefix)
+import qualified Data.Text as T (pack, unpack, stripPrefix)
+import Data.Text (Text)
+import Data.Monoid ((<>))
 
 -- --------------------------------------------------------------------
 -- Command line options
 --
 
-data Flag =  VersionF | SessionN String | EmptySession | DefaultSession | Help | Verbosity String
+data Flag =  VersionF | SessionN Text | EmptySession | DefaultSession | Help | Verbosity Text
        deriving (Show,Eq)
 
 options :: [OptDescr Flag]
@@ -92,7 +94,7 @@
                 "Start with empty session"
          ,   Option ['d'] ["defaultSession"] (NoArg DefaultSession)
                 "Start with default session (can be used together with a source file)"
-         ,   Option ['l'] ["loadSession"] (ReqArg SessionN "NAME")
+         ,   Option ['l'] ["loadSession"] (ReqArg (SessionN . T.pack) "NAME")
                 "Load session"
 
          ,   Option ['h'] ["help"] (NoArg Help)
@@ -100,16 +102,16 @@
          ,   Option ['v'] ["version"] (NoArg VersionF)
                 "Show the version number of ide"
 
-         ,   Option ['e'] ["verbosity"] (ReqArg Verbosity "Verbosity")
+         ,   Option ['e'] ["verbosity"] (ReqArg (Verbosity . T.pack) "Verbosity")
              "One of DEBUG, INFO, NOTICE, WARNING, ERROR, CRITICAL, ALERT, EMERGENCY"]
 
 
 header = "Usage: leksah [OPTION...] [file(.lkshs|.lkshw|.hs|.lhs)]"
 
-ideOpts :: [String] -> IO ([Flag], [String])
+ideOpts :: [Text] -> IO ([Flag], [Text])
 ideOpts argv =
-    case getOpt Permute options argv of
-          (o,n,[]  ) -> return (o,n)
+    case getOpt Permute options $ map T.unpack argv of
+          (o,n,[]  ) -> return (o,map T.pack n)
           (_,_,errs) -> ioError $ userError $ concat errs ++ usageInfo header options
 
 -- ---------------------------------------------------------------------
@@ -141,16 +143,16 @@
     dataDir         <- getDataDir
     args            <-  getArgs
 
-    (o,files)       <-  ideOpts args
+    (o,files)       <-  ideOpts $ map T.pack args
     isFirstStart    <-  liftM not $ hasSavedConfigFile standardPreferencesFilename
     let sessions      =   catMaybes $ map (\x -> case x of
                                         SessionN s -> Just s
                                         _          -> Nothing) o
 
-    let sessionFPs    =   filter (\f -> snd (splitExtension f) == leksahSessionFileExtension) files
-    let workspaceFPs  =   filter (\f -> snd (splitExtension f) == leksahWorkspaceFileExtension) files
+    let sessionFPs    =   filter (\f -> snd (splitExtension f) == leksahSessionFileExtension) $ map T.unpack files
+    let workspaceFPs  =   filter (\f -> snd (splitExtension f) == leksahWorkspaceFileExtension) $ map T.unpack files
     let sourceFPs     =   filter (\f -> let (_,s) = splitExtension f
-                                        in s == ".hs" ||  s == ".lhs" || s == ".chs") files
+                                        in s == ".hs" ||  s == ".lhs" || s == ".chs") $ map T.unpack files
     let mbWorkspaceFP'=  case workspaceFPs of
                                 [] ->  Nothing
                                 w:_ -> Just w
@@ -164,7 +166,7 @@
                                 then return (Just spath,Nothing)
                                 else return (Nothing,Just fp)
     let ssession =  case sessions of
-                        (s:_) -> s ++ leksahSessionFileExtension
+                        (s:_) -> T.unpack s <> leksahSessionFileExtension
                         _     -> if null sourceFPs
                                         then standardSessionFilename
                                         else emptySessionFilename
@@ -185,12 +187,12 @@
                                     _           -> Nothing) o
     let verbosity       =  case verbosity' of
                                [] -> INFO
-                               h:_ -> read h
+                               h:_ -> read $ T.unpack h
     updateGlobalLogger rootLoggerName (\ l -> setLevel verbosity l)
     when (elem VersionF o)
-        (sysMessage Normal $ "Leksah the Haskell IDE, version " ++ showVersion version)
+        (sysMessage Normal $ "Leksah the Haskell IDE, version " <> T.pack (showVersion version))
     when (elem Help o)
-        (sysMessage Normal $ "Leksah the Haskell IDE " ++ usageInfo header options)
+        (sysMessage Normal $ "Leksah the Haskell IDE " <> T.pack (usageInfo header options))
 
     prefsPath       <- getConfigFilePathForLoad standardPreferencesFilename Nothing dataDir
     prefs           <- readPrefs prefsPath
@@ -199,7 +201,7 @@
 
 handleExceptions inner =
   catch inner (\(exception :: SomeException) -> do
-    sysMessage Normal ("leksah: internal IDE error: " ++ show exception)
+    sysMessage Normal ("leksah: internal IDE error: " <> T.pack (show exception))
     exitFailure
   )
 
@@ -213,7 +215,7 @@
     when rtsSupportsBoundThreads
         (sysMessage Normal "Linked with -threaded")
     timeout <- timeoutAddFull (yield >> return True) priorityHigh 10
-    mapM_ (sysMessage Normal) st
+    mapM_ (sysMessage Normal . T.pack) st
     initGtkRc
     dataDir       <- getDataDir
     mbStartupPrefs <- if not isFirstStart
@@ -232,16 +234,58 @@
             Nothing           -> return ()
             Just startupPrefs -> startMainWindow yiControl sessionFP mbWorkspaceFP sourceFPs
                                     startupPrefs isFirstStart
-    unless rtsSupportsBoundThreads $ postGUIAsync mainLoop
     debugM "leksah" "starting mainGUI"
     mainGUI
     debugM "leksah" "finished mainGUI"
 
-mainLoop :: IO ()
-mainLoop = eventsPending >>= loop 50
+mainLoop :: IO () -> IO ()
+mainLoop = if rtsSupportsBoundThreads then mainLoopThreaded else mainLoopSingleThread
+
+mainLoopThreaded :: IO () -> IO ()
+mainLoopThreaded onIdle = loop
+    where
+        loop = do
+            quit <- loopTillIdle
+            if quit
+                then return ()
+                else do
+                    active <- newEmptyMVar
+                    mvarSentIdleMessage <- newEmptyMVar
+                    idleThread <- forkIO $ do
+                        threadDelay 50000
+                        isActive <- isJust <$> tryTakeMVar active
+                        unless isActive $ do
+                            putMVar mvarSentIdleMessage ()
+                            postGUIAsync onIdle
+                    quit <- mainIteration
+                    putMVar active ()
+                    if quit
+                        then return ()
+                        else do
+                            -- If an idle message was sent then wait again
+                            sentIdleMessage <- isJust <$> tryTakeMVar mvarSentIdleMessage
+                            quit <- if sentIdleMessage
+                                then mainIteration
+                                else return False
+                            if quit
+                                then return ()
+                                else loop
+        loopTillIdle = do
+            pending <- eventsPending
+            if pending == 0
+                then return False
+                else do
+                    quit <- loopn (pending + 2)
+                    if quit
+                        then return True
+                        else loopTillIdle
+
+mainLoopSingleThread :: IO () -> IO ()
+mainLoopSingleThread onIdle = eventsPending >>= loop False 50
   where
-    loop :: Int -> Int -> IO ()
-    loop delay n = do
+    loop :: Bool -> Int -> Int -> IO ()
+    loop False delay 0 | delay > 2000 = onIdle >> loop True delay 0
+    loop isIdle delay n = do
         quit <- if n > 0
                     then do
                         timeout <- timeoutAddFull (yield >> return True) priorityHigh 10
@@ -257,23 +301,25 @@
                 pending <- eventsPending
                 if pending > 0
                     then do
-                        loop 50 pending
+                        loop False 50 pending
                     else do
                         threadDelay delay
-                        eventsPending >>= loop (if n > 0
-                                                    then 50
-                                                    else min (delay+delay) 50000)
-    loopn :: Int -> IO Bool
-    loopn 0 = return False
-    loopn n = do
-        quit <- mainIterationDo False
-        if quit
-            then return True
-            else loopn (n - 1)
+                        eventsPending >>= loop isIdle (if n > 0
+                                                            then 50
+                                                            else min (delay+delay) 50000)
 
+loopn :: Int -> IO Bool
+loopn 0 = return False
+loopn n = do
+    quit <- mainIterationDo False
+    if quit
+        then return True
+        else loopn (n - 1)
+
 startMainWindow :: Yi.Control -> FilePath -> Maybe FilePath -> [FilePath] ->
                         Prefs -> Bool -> IO ()
 startMainWindow yiControl sessionFP mbWorkspaceFP sourceFPs startupPrefs isFirstStart = do
+    timeout <- timeoutAddFull (yield >> return True) priorityHigh 10
     debugM "leksah" "startMainWindow"
     osxApp <- OSX.applicationNew
     uiManager   <-  uiManagerNew
@@ -281,16 +327,16 @@
     dataDir       <- getDataDir
     candyPath   <-  getConfigFilePathForLoad
                         (case sourceCandy startupPrefs of
-                            (_,name)   ->   name ++ leksahCandyFileExtension) Nothing dataDir
+                            (_,name)   ->   T.unpack name <> leksahCandyFileExtension) Nothing dataDir
     candySt     <-  parseCandy candyPath
     -- keystrokes
-    keysPath    <-  getConfigFilePathForLoad (keymapName startupPrefs ++ leksahKeymapFileExtension) Nothing dataDir
+    keysPath    <-  getConfigFilePathForLoad (T.unpack (keymapName startupPrefs) <> leksahKeymapFileExtension) Nothing dataDir
     keyMap      <-  parseKeymap keysPath
     let accelActions = setKeymap (keyMap :: KeymapI) mkActions
     specialKeys <-  buildSpecialKeys keyMap accelActions
 
     win         <-  windowNew
-    widgetSetName win "Leksah Main Window"
+    widgetSetName win ("Leksah Main Window"::Text)
     let fs = FrameState
             {   windows       =   [win]
             ,   uiManager     =   uiManager
@@ -341,7 +387,7 @@
     reflectIDE (makeMenu uiManager accelActions menuDescription') ideR
     nb               <-  reflectIDE (newNotebook []) ideR
     after nb switchPage (\i -> reflectIDE (handleNotebookSwitch nb i) ideR)
-    widgetSetName nb $"root"
+    widgetSetName nb ("root"::Text)
     on win deleteEvent . liftIO $ reflectIDE quit ideR >> return True
     reflectIDE (instrumentWindow win startupPrefs (castToWidget nb)) ideR
     reflectIDE (do
@@ -396,11 +442,16 @@
             workspaceTryQuiet $ workspaceAddPackage' welcomeCabal >> return ()
             fileOpenThis welcomeMain) ideR
     reflectIDE (initInfo (modifyIDE_ (\ide -> ide{currentState = IsRunning}))) ideR
-    timeoutAddFull (do
+    timeoutRemove timeout
+    postGUIAsync . mainLoop $
         reflectIDE (do
             currentPrefs <- readIDE prefs
             when (backgroundBuild currentPrefs) $ backgroundMake) ideR
-        return True) priorityDefaultIdle 1000
+--    timeoutAddFull (do
+--        reflectIDE (do
+--            currentPrefs <- readIDE prefs
+--            when (backgroundBuild currentPrefs) $ backgroundMake) ideR
+--        return True) priorityDefaultIdle 1000
     reflectIDE (triggerEvent ideR (Sensitivity [(SensitivityInterpreting, False)])) ideR
     return ()
 --    mainGUI
@@ -424,7 +475,7 @@
             (paraName <<<- ParaName "URL from which to download prebuilt metadata" $ emptyParams)
             retrieveURL
             (\b a -> a{retrieveURL = b})
-            (stringEditor (\ _ -> True) True)
+            (textEditor (\ _ -> True) True)
     ,   mkField
             (paraName <<<- ParaName "Strategy for downloading prebuilt metadata" $ emptyParams)
             retrieveStrategy
@@ -443,18 +494,18 @@
     dialog      <- dialogNew
     setLeksahIcon dialog
     set dialog [
-        windowTitle := "Welcome to Leksah, the Haskell IDE",
+        windowTitle := ("Welcome to Leksah, the Haskell IDE"::Text),
         windowWindowPosition := WinPosCenter]
-    dialogAddButton dialog "gtk-ok" ResponseOk
-    dialogAddButton dialog "gtk-cancel" ResponseCancel
+    dialogAddButton dialog ("gtk-ok"::Text) ResponseOk
+    dialogAddButton dialog ("gtk-cancel"::Text) ResponseCancel
 #ifdef MIN_VERSION_gtk3
     vb          <- dialogGetContentArea dialog
 #else
     vb          <- dialogGetUpper dialog
 #endif
     label       <- labelNew (Just (
-        "Before you start using Leksah it will collect and download metadata about your installed Haskell packages.\n" ++
-        "You can add folders under which you have sources for Haskell packages not available from Hackage."))
+        "Before you start using Leksah it will collect and download metadata about your installed Haskell packages.\n" <>
+        "You can add folders under which you have sources for Haskell packages not available from Hackage."::Text))
     (widget, setInj, getExt,notifier) <- buildEditor (fDescription configDir) prefs
     boxPackStart (castToBox vb) label PackNatural 7
     sw <- scrolledWindowNew Nothing Nothing
@@ -502,7 +553,7 @@
     dialog      <- dialogNew
     setLeksahIcon dialog
     set dialog [
-        windowTitle := "Leksah: Updating Metadata",
+        windowTitle := ("Leksah: Updating Metadata"::Text),
         windowWindowPosition := WinPosCenter,
         windowDeletable := False]
 #ifdef MIN_VERSION_gtk3
@@ -511,13 +562,13 @@
     vb          <- dialogGetUpper dialog
 #endif
     progressBar <- progressBarNew
-    progressBarSetText progressBar "Please wait while Leksah collects information about Haskell packages on your system"
+    progressBarSetText progressBar ("Please wait while Leksah collects information about Haskell packages on your system"::Text)
     progressBarSetFraction progressBar 0.0
     boxPackStart (castToBox vb) progressBar PackGrow 7
     forkIO $ do
             logger <- getRootLogger
             let verbosity = case getLevel logger of
-                                Just level -> ["--verbosity=" ++ show level]
+                                Just level -> ["--verbosity=" <> T.pack (show level)]
                                 Nothing    -> []
             (output, pid) <- runTool "leksah-server" (["-sbo", "+RTS", "-N2", "-RTS"] ++ verbosity) Nothing
             output $$ CL.mapM_ (update progressBar)
diff --git a/src/IDE/LogRef.hs b/src/IDE/LogRef.hs
--- a/src/IDE/LogRef.hs
+++ b/src/IDE/LogRef.hs
@@ -69,11 +69,12 @@
 import Data.IORef (atomicModifyIORef, IORef, readIORef)
 import Data.Text (Text)
 import Control.Applicative ((<$>))
-import qualified Data.Text as T (unpack, unlines, pack, null)
+import qualified Data.Text as T
+       (stripPrefix, isPrefixOf, unpack, unlines, pack, null)
 import Data.Monoid ((<>))
 
-showSourceSpan :: LogRef -> String
-showSourceSpan = displaySrcSpan . logRefSrcSpan
+showSourceSpan :: LogRef -> Text
+showSourceSpan = T.pack . displaySrcSpan . logRefSrcSpan
 
 selectRef :: Maybe LogRef -> IDEAction
 selectRef (Just ref) = do
@@ -109,7 +110,7 @@
 unmarkLogRefs = do
     forOpenLogRefs $ \index logRef (IDEBuffer {sourceView = sv}) -> do
             buf     <-  getBuffer sv
-            removeTagByName buf (show (logRefType logRef) ++ show index)
+            removeTagByName buf (T.pack $ show (logRefType logRef) ++ show index)
 
 setErrorList :: [LogRef] -> IDEAction
 setErrorList errs = do
@@ -309,9 +310,9 @@
 
 data BuildError =   BuildLine
                 |   EmptyLine
-                |   ErrorLine SrcSpan LogRefType String
-                |   WarningLine String
-                |   OtherLine String
+                |   ErrorLine SrcSpan LogRefType Text
+                |   WarningLine Text
+                |   OtherLine Text
 
 buildLineParser :: CharParser () BuildError
 buildLineParser = try (do
@@ -331,7 +332,7 @@
                 symbol "Warning:"
                 return WarningRef)
             <|> return ErrorRef
-        text <- many anyChar
+        text <- T.pack <$> many anyChar
         return (ErrorLine span refType text))
     <|> try (do
         whiteSpace
@@ -340,10 +341,10 @@
     <|> try (do
         whiteSpace
         symbol "Warning:"
-        text <- many anyChar
-        return (WarningLine ("Warning:" ++ text)))
+        text <- T.pack <$> many anyChar
+        return (WarningLine ("Warning:" <> text)))
     <|> try (do
-        text <- many anyChar
+        text <- T.pack <$> many anyChar
         eof
         return (OtherLine text))
     <?> "buildLineParser"
@@ -455,14 +456,14 @@
     defaultLogLaunch <- lift $ getDefaultLogLaunch
     logOutput defaultLogLaunch
 
-logOutputPane :: String -> IORef [Text] -> C.Sink ToolOutput IDEM ()
+logOutputPane :: Text -> IORef [Text] -> C.Sink ToolOutput IDEM ()
 logOutputPane command buffer = do
     defaultLogLaunch <- lift $ getDefaultLogLaunch
     result <- catMaybes <$> logOutputLines defaultLogLaunch paneLineLogger
     when (not $ null result) $ do
         new <- liftIO . atomicModifyIORef buffer $ \x -> let new = x ++ result in (new, new)
         mbURI <- lift $ readIDE autoURI
-        unless (isJust mbURI) . lift . postSyncIDE . setOutput command $ T.unpack $ T.unlines new
+        unless (isJust mbURI) . lift . postSyncIDE . setOutput command $ T.unlines new
 
 logOutputForBuild :: IDEPackage
                   -> Bool
@@ -479,7 +480,7 @@
         let errorNum    =   length (filter isError errs)
         let warnNum     =   length errs - errorNum
         triggerEventIDE (StatusbarChanged [CompartmentState
-            (show errorNum ++ " Errors, " ++ show warnNum ++ " Warnings"), CompartmentBuild False])
+            (T.pack $ show errorNum ++ " Errors, " ++ show warnNum ++ " Warnings"), CompartmentBuild False])
         unless (backgroundBuild || (not jumpToWarnings && errorNum == 0)) nextError
         return errs) ideR
   where
@@ -492,22 +493,22 @@
                 let nonErrorPrefixes = ["Linking ", "ar:", "ld:", "ld warning:"]
                 tag <- case parsed of
                     Right BuildLine -> return InfoTag
-                    Right (OtherLine text) | "Linking " `isPrefixOf` text -> do
+                    Right (OtherLine text) | "Linking " `T.isPrefixOf` text -> do
                         -- when backgroundBuild $ lift interruptProcess
                         reflectIDE (do
                                 setErrorList $ reverse errs
                             ) ideR
                         return InfoTag
-                    Right (OtherLine text) | any (`isPrefixOf` text) nonErrorPrefixes -> do
+                    Right (OtherLine text) | any (`T.isPrefixOf` text) nonErrorPrefixes -> do
                         return InfoTag
                     _ -> return ErrorTag
                 lineNr <- Log.appendLog log logLaunch (line <> "\n") tag
                 case (parsed, errs) of
                     (Left e,_) -> do
-                        sysMessage Normal (show e)
+                        sysMessage Normal . T.pack $ show e
                         return (log, False, errs)
                     (Right ne@(ErrorLine span refType str),_) ->
-                        return (log, True, ((LogRef span package (T.pack str) (lineNr,lineNr) refType):errs))
+                        return (log, True, ((LogRef span package str (lineNr,lineNr) refType):errs))
                     (Right (OtherLine str1),(LogRef span rootPath str (l1,l2) refType):tl) ->
                         if inError
                             then return (log, True, ((LogRef span
@@ -552,7 +553,7 @@
                 return (log, inError, errs)
 
 
---logOutputLines :: String -- ^ logLaunch
+--logOutputLines :: Text -- ^ logLaunch
 --               -> (LogLaunch -> ToolOutput -> IDEM a)
 --               -> [ToolOutput]
 --               -> IDEM [a]
@@ -599,14 +600,14 @@
 
 logOutputForContext :: IDEPackage
                     -> LogLaunch                   -- ^ loglaunch
-                    -> (String -> [SrcSpan])
+                    -> (Text -> [SrcSpan])
                     -> C.Sink ToolOutput IDEM ()
 logOutputForContext package loglaunch getContexts = do
     refs <- fmap catMaybes $ logOutputLines loglaunch (\log logLaunch out -> do
         case out of
             ToolOutput line -> do
                 logLineNumber <- liftIO $ Log.appendLog log logLaunch (line <> "\n") LogTag
-                let contexts = getContexts $ T.unpack line
+                let contexts = getContexts line
                 if null contexts
                     then return Nothing
                     else return $ Just $ LogRef (last contexts) package line (logLineNumber, logLineNumber) ContextRef
@@ -620,7 +621,7 @@
 logOutputForLiveContext :: IDEPackage
                         -> LogLaunch           -- ^ loglaunch
                         -> C.Sink ToolOutput IDEM ()
-logOutputForLiveContext package logLaunch = logOutputForContext package logLaunch getContexts
+logOutputForLiveContext package logLaunch = logOutputForContext package logLaunch (getContexts . T.unpack)
     where
         getContexts [] = []
         getContexts line@(x:xs) = case stripPrefix "Stopped at " line of
@@ -641,8 +642,8 @@
                             -> C.Sink ToolOutput IDEM ()
 logOutputForHistoricContext package logLaunch = logOutputForContext package logLaunch getContexts
     where
-        getContexts line = case stripPrefix "Logged breakpoint at " line of
-            Just rest -> case parse srcSpanParser "" rest of
+        getContexts line = case T.stripPrefix "Logged breakpoint at " line of
+            Just rest -> case parse srcSpanParser "" $ T.unpack rest of
                 Right desc -> [desc]
                 _          -> []
             _ -> []
diff --git a/src/IDE/Metainfo/Provider.hs b/src/IDE/Metainfo/Provider.hs
--- a/src/IDE/Metainfo/Provider.hs
+++ b/src/IDE/Metainfo/Provider.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE CPP, ScopedTypeVariables #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Metainfo.Provider
@@ -56,13 +57,9 @@
 import Text.Regex.TDFA
 import qualified Text.Regex.TDFA as Regex
 import System.IO.Unsafe (unsafePerformIO)
-import Text.Regex.TDFA.String (execute,compile)
+import Text.Regex.TDFA.Text (execute,compile)
 import Data.Binary.Shared (decodeSer)
-#if MIN_VERSION_Cabal(1,16,0)
 import Language.Haskell.Extension (KnownExtension)
-#else
-import Language.Haskell.Extension (knownExtensions)
-#endif
 import Distribution.Text (display)
 import IDE.Core.Serializable ()
 import Data.Map (Map(..))
@@ -72,8 +69,10 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad.Trans.Class (MonadTrans(..))
 import Distribution.PackageDescription (hsSourceDirs)
-
-trace a b = b
+import System.Log.Logger (infoM)
+import Data.Text (Text)
+import qualified Data.Text as T (null, isPrefixOf, unpack, pack)
+import Data.Monoid ((<>))
 
 -- ---------------------------------------------------------------------
 -- Updating metadata
@@ -94,7 +93,8 @@
                 updateWorkspaceInfo' False $ \ _ -> do
                     triggerEventIDE (InfoChanged True) >> return ()
 
-                    trace "blah" $ continuation
+                    liftIO $ infoM "leksah" "initInfo continuing"
+                    continuation
         else do
             ideMessage Normal "Now loading metadata ..."
             loadSystemInfo
@@ -104,19 +104,22 @@
                 continuation
 
 updateSystemInfo :: IDEAction
-updateSystemInfo     = trace "update sys info called" $ do
+updateSystemInfo     = do
+    liftIO $ infoM "leksah" "update sys info called"
     updateSystemInfo' False $ \ _ ->
         updateWorkspaceInfo' False $ \ _ -> do
             triggerEventIDE (InfoChanged False) >> return ()
 
 rebuildSystemInfo :: IDEAction
-rebuildSystemInfo    =  trace "rebuild sys info called" $ do
+rebuildSystemInfo    = do
+    liftIO $ infoM "leksah" "rebuild sys info called"
     updateSystemInfo' True $ \ _ ->
         updateWorkspaceInfo' True $ \ _ ->
             triggerEventIDE (InfoChanged False) >> return ()
 
 updateWorkspaceInfo :: IDEAction
-updateWorkspaceInfo = trace "update workspace info called" $ do
+updateWorkspaceInfo = do
+    liftIO $ infoM "leksah" "update workspace info called"
     currentState' <- readIDE currentState
     case currentState' of
         IsStartingUp -> return ()
@@ -125,7 +128,8 @@
                 triggerEventIDE (InfoChanged False) >> return ()
 
 rebuildWorkspaceInfo :: IDEAction
-rebuildWorkspaceInfo = trace "rebuild workspace info called" $ do
+rebuildWorkspaceInfo = do
+    liftIO $ infoM "leksah" "rebuild workspace info called"
     updateWorkspaceInfo' True $ \ _ -> do
         triggerEventIDE (InfoChanged False) >> return ()
 
@@ -171,14 +175,14 @@
                                                     (map fromJust
                                                         $ filter isJust newPackageInfos)
                         let psmap3      =   foldr (\e m -> Map.delete e m) psmap2 trashPackages
-                        let scope :: PackScope (Map String [Descr])
+                        let scope :: PackScope (Map Text [Descr])
                                         =   foldr buildScope (PackScope Map.empty symEmpty)
                                                 (Map.elems psmap3)
                         modifyIDE_ (\ide -> ide{systemInfo = Just (GenScopeC (addOtherToScope scope False))})
                         continuation True
     ideMessage Normal "Finished updating system metadata"
 
-getEmptyDefaultScope :: Map String [Descr]
+getEmptyDefaultScope :: Map Text [Descr]
 getEmptyDefaultScope = symEmpty
 --
 -- | Rebuilds system info
@@ -201,7 +205,8 @@
     systemInfo'         <- getSystemInfo
     case mbWorkspace of
         Nothing ->  do
-            trace "no workspace" $ modifyIDE_ (\ide -> ide{workspaceInfo = Nothing, packageInfo = Nothing})
+            liftIO $ infoM "leksah" "updateWorkspaceInfo' no workspace"
+            modifyIDE_ (\ide -> ide{workspaceInfo = Nothing, packageInfo = Nothing})
             continuation False
         Just ws -> do
             updatePackageInfos rebuild (wsAllPackages ws) $ \ _ packDescrs -> do
@@ -211,9 +216,9 @@
                                         Nothing -> []
                                         Just (GenScopeC (PackScope pdmap _)) ->
                                             catMaybes $ map (\ pid -> pid `Map.lookup` pdmap)  dependPackIds
-                let scope1 :: PackScope (Map String [Descr])
+                let scope1 :: PackScope (Map Text [Descr])
                                 =   foldr buildScope (PackScope Map.empty symEmpty) packDescrs
-                let scope2 :: PackScope (Map String [Descr])
+                let scope2 :: PackScope (Map Text [Descr])
                                 =   foldr buildScope (PackScope Map.empty symEmpty) packDescrsI
                 modifyIDE_ (\ide -> ide{workspaceInfo = Just
                     (GenScopeC (addOtherToScope scope1 True), GenScopeC(addOtherToScope scope2 False))})
@@ -238,9 +243,9 @@
                                             if (elem (pdPackage pd) workspacePackageIds)
                                                 then find (\pd' -> pdPackage pd == pdPackage pd') packDescrs
                                                 else Nothing) impPackDescrs
-                                        scope1 :: PackScope (Map String [Descr])
+                                        scope1 :: PackScope (Map Text [Descr])
                                                 =   buildScope pd (PackScope Map.empty symEmpty)
-                                        scope2 :: PackScope (Map String [Descr])
+                                        scope2 :: PackScope (Map Text [Descr])
                                                 =   foldr buildScope (PackScope Map.empty symEmpty)
                                                         (impPackDescrs' ++ impPackDescrs'')
                                         in modifyIDE_ (\ide -> ide{packageInfo = Just
@@ -259,8 +264,8 @@
                 updatePackageInfos' (packDescr : collector) rebuild tail continuation
 
 updatePackageInfo :: Bool -> IDEPackage -> (Bool -> PackageDescr -> IDEAction) -> IDEAction
-updatePackageInfo rebuild idePack continuation =
-    trace ("updatePackageInfo " ++ show (ipdPackageId idePack)) $ do
+updatePackageInfo rebuild idePack continuation = do
+    liftIO $ infoM "leksah" ("updatePackageInfo " ++ show rebuild ++ " " ++ show (ipdPackageId idePack))
     workspInfoCache'     <- readIDE workspInfoCache
     let (packageMap, ic) =  case pi  `Map.lookup` workspInfoCache' of
                                 Nothing -> (Map.empty,True)
@@ -286,16 +291,16 @@
     modToUpdate <- if rebuild
                             then return modWithSources
                             else liftIO $ figureOutRealSources idePack modWithSources
-    trace ("updatePackageInfo modToUpdate " ++ show (map (display.fst) modToUpdate)) $
-     callCollectorWorkspace
+    liftIO . infoM "leksah" $ "updatePackageInfo modToUpdate " ++ show (map (display.fst) modToUpdate)
+    callCollectorWorkspace
         rebuild
         (dropFileName (ipdCabalFile idePack))
         (ipdPackageId idePack)
-        (map (\(x,y) -> (display x,y)) modToUpdate)
+        (map (\(x,y) -> (T.pack $ display x,y)) modToUpdate)
         (\ b -> do
             buildDepends         <- liftIO $ findFittingPackages (ipdDepends idePack)
             collectorPath        <- liftIO $ getCollectorPath
-            let packageCollectorPath = collectorPath </> packageIdentifierToString pi
+            let packageCollectorPath = collectorPath </> T.unpack (packageIdentifierToString pi)
             (moduleDescrs,packageMap, changed, modWithout)
                                  <- liftIO $ foldM
                                         (getModuleDescr packageCollectorPath)
@@ -310,13 +315,13 @@
                 pdBuildDepends   = buildDepends}))
     where
         basePath =  normalise $ (takeDirectory (ipdCabalFile idePack))
-        srcDirs' bi =  map (basePath </>) (hsSourceDirs bi)
+        srcDirs' bi =  map (basePath </>) ("dist/build":(hsSourceDirs bi))
         pi = ipdPackageId idePack
 
 figureOutRealSources :: IDEPackage -> [(ModuleName,FilePath)] -> IO [(ModuleName,FilePath)]
 figureOutRealSources idePack modWithSources = do
     collectorPath <- getCollectorPath
-    let packageCollectorPath = collectorPath </> packageIdentifierToString (ipdPackageId idePack)
+    let packageCollectorPath = collectorPath </> T.unpack (packageIdentifierToString $ ipdPackageId idePack)
     filterM (ff packageCollectorPath) modWithSources
     where
         ff packageCollectorPath (md ,fp) =  do
@@ -348,8 +353,8 @@
                     if modificationTime == eTime
                         then return (mdescr:modDescrs,packageMap,changed,problemMods)
                         else do
-                            mbNewDescr  <- trace ("loadInfo: " ++ display modName) $
-                                                loadInfosForModule moduleCollectorPath
+                            liftIO . infoM "leksah" $ "getModuleDescr loadInfo: " ++ display modName
+                            mbNewDescr <- loadInfosForModule moduleCollectorPath
                             case mbNewDescr of
                                 Just newDescr -> return (newDescr:modDescrs,
                                                     Map.insert modName (modificationTime,mbFilePath,newDescr) packageMap,
@@ -382,20 +387,20 @@
 --
 loadInfosForPackage :: FilePath -> PackageIdentifier -> IO (Maybe PackageDescr)
 loadInfosForPackage dirPath pid = do
-    let filePath = dirPath </> packageIdentifierToString pid ++ leksahMetadataSystemFileExtension
-    let filePath2 = dirPath </> packageIdentifierToString pid ++ leksahMetadataPathFileExtension
+    let filePath = dirPath </> T.unpack (packageIdentifierToString pid) ++ leksahMetadataSystemFileExtension
+    let filePath2 = dirPath </> T.unpack (packageIdentifierToString pid) ++ leksahMetadataPathFileExtension
     exists <- doesFileExist filePath
     if exists
         then catch (do
             file            <-  openBinaryFile filePath ReadMode
-            trace ("now loading metadata for package " ++ packageIdentifierToString pid) return ()
+            liftIO . infoM "leksah" . T.unpack $ "now loading metadata for package " <> packageIdentifierToString pid
             bs              <-  BSL.hGetContents file
             let (metadataVersion'::Integer, packageInfo::PackageDescr) = decodeSer bs
             if metadataVersion /= metadataVersion'
                 then do
                     hClose file
                     throwIDE ("Metadata has a wrong version."
-                            ++  " Consider rebuilding metadata with: leksah-server -osb +RTS -N2 -RTS")
+                            <>  " Consider rebuilding metadata with: leksah-server -osb +RTS -N2 -RTS")
                 else do
                     packageInfo `deepseq` (hClose file)
                     exists'  <-  doesFileExist filePath2
@@ -406,10 +411,10 @@
                     return (Just packageInfo'))
             (\ (e :: SomeException) -> do
                 sysMessage Normal
-                    ("loadInfosForPackage: " ++ packageIdentifierToString pid ++ " Exception: " ++ show e)
+                    ("loadInfosForPackage: " <> packageIdentifierToString pid <> " Exception: " <> T.pack (show e))
                 return Nothing)
         else do
-            sysMessage Normal $"packageInfo not found for " ++ packageIdentifierToString pid
+            sysMessage Normal $"packageInfo not found for " <> packageIdentifierToString pid
             return Nothing
 
 injectSourceInPack :: Maybe FilePath -> PackageDescr -> PackageDescr
@@ -442,13 +447,13 @@
                 then do
                     hClose file
                     throwIDE ("Metadata has a wrong version."
-                            ++  " Consider rebuilding metadata with -r option")
+                           <> " Consider rebuilding metadata with -r option")
                 else do
                     moduleInfo `deepseq` (hClose file)
                     return (Just moduleInfo))
-            (\ (e :: SomeException) -> do sysMessage Normal ("loadInfosForModule: " ++ show e); return Nothing)
+            (\ (e :: SomeException) -> do sysMessage Normal (T.pack $ "loadInfosForModule: " ++ show e); return Nothing)
         else do
-            sysMessage Normal $"moduleInfo not found for " ++ filePath
+            sysMessage Normal $ "moduleInfo not found for " <> T.pack filePath
             return Nothing
 
 findFittingPackages :: [Dependency] -> IO [PackageIdentifier]
@@ -483,7 +488,7 @@
 --
 -- | Lookup of an identifier description
 --
-getIdentifierDescr :: (SymbolTable alpha, SymbolTable beta)  => String -> alpha   -> beta   -> [Descr]
+getIdentifierDescr :: (SymbolTable alpha, SymbolTable beta)  => Text -> alpha   -> beta   -> [Descr]
 getIdentifierDescr str st1 st2 =
     let r1 = str `symLookup` st1
         r2 = str `symLookup` st2
@@ -492,9 +497,9 @@
 --
 -- | Lookup of an identifiers starting with the specified prefix and return a list.
 --
-getIdentifiersStartingWith :: (SymbolTable alpha , SymbolTable beta)  => String -> alpha   -> beta   -> [String]
+getIdentifiersStartingWith :: (SymbolTable alpha , SymbolTable beta)  => Text -> alpha   -> beta   -> [Text]
 getIdentifiersStartingWith prefix st1 st2 =
-    takeWhile (isPrefixOf prefix) $
+    takeWhile (T.isPrefixOf prefix) $
         if memberLocal || memberGlobal then
             prefix : Set.toAscList names
             else
@@ -504,7 +509,7 @@
         (_, memberGlobal, globalNames) = Set.splitMember prefix (symbols st2)
         names = Set.union globalNames localNames
 
-getCompletionOptions :: String -> IDEM [String]
+getCompletionOptions :: Text -> IDEM [Text]
 getCompletionOptions prefix = do
     workspaceInfo' <- getWorkspaceInfo
     case workspaceInfo' of
@@ -512,13 +517,13 @@
         Just ((GenScopeC (PackScope _ symbolTable1)),(GenScopeC (PackScope _ symbolTable2))) ->
             return $ getIdentifiersStartingWith prefix symbolTable1 symbolTable2
 
-getDescription :: String -> IDEM String
+getDescription :: Text -> IDEM Text
 getDescription name = do
     workspaceInfo' <- getWorkspaceInfo
     case workspaceInfo' of
         Nothing -> return ""
         Just ((GenScopeC (PackScope _ symbolTable1)),(GenScopeC (PackScope _ symbolTable2))) ->
-            return ((foldr (\d f -> shows (Present d) .  showChar '\n' . f) id
+            return $ T.pack ((foldr (\d f -> shows (Present d) .  showChar '\n' . f) id
                 (getIdentifierDescr name symbolTable1 symbolTable2)) "")
 
 getPackageInfo :: IDEM (Maybe (GenScope, GenScope))
@@ -539,18 +544,26 @@
         then do
             packageInfo' <- getPackageInfo
             case packageInfo' of
-                Nothing -> trace "getPackageImportInfo: no package info" $ return Nothing
+                Nothing -> do
+                    liftIO $ infoM "leksah" "getPackageImportInfo: no package info"
+                    return Nothing
                 Just ((GenScopeC (PackScope pdmap _)),_) -> do
                      case Map.lookup (ipdPackageId idePack) pdmap of
-                        Nothing -> trace "getPackageImportInfo: package not found in package" $ return Nothing
+                        Nothing -> do
+                            liftIO $ infoM "leksah" "getPackageImportInfo: package not found in package"
+                            return Nothing
                         Just pd -> buildIt pd systemInfo'
         else do
             workspaceInfo <- getWorkspaceInfo
             case workspaceInfo of
-                Nothing -> trace "getPackageImportInfo: no workspace info" $ return Nothing
+                Nothing -> do
+                    liftIO $ infoM "leksah" "getPackageImportInfo: no workspace info"
+                    return Nothing
                 Just ((GenScopeC (PackScope pdmap _)),_) ->
                     case Map.lookup (ipdPackageId idePack) pdmap of
-                        Nothing -> trace "getPackageImportInfo: package not found in workspace" $ return Nothing
+                        Nothing -> do
+                            liftIO $ infoM "leksah" "getPackageImportInfo: package not found in workspace"
+                            return Nothing
                         Just pd -> buildIt pd systemInfo'
 
     where
@@ -558,21 +571,23 @@
         filterPrivate md = md{mdIdDescriptions = filter dscExported (mdIdDescriptions md)}
         buildIt pd systemInfo' =
                 case systemInfo' of
-                    Nothing -> trace "getPackageImportInfo: no system info" $ return Nothing
+                    Nothing -> do
+                        liftIO $ infoM "leksah" "getPackageImportInfo: no system info"
+                        return Nothing
                     Just (GenScopeC (PackScope pdmap' _)) ->
                         let impPackDescrs = catMaybes $ map (\ pid -> pid `Map.lookup` pdmap')
                                                 (pdBuildDepends pd)
                             pd' = pd{pdModules = map filterPrivate (pdModules pd)}
-                            scope1 :: PackScope (Map String [Descr])
+                            scope1 :: PackScope (Map Text [Descr])
                                             =   buildScope pd (PackScope Map.empty symEmpty)
-                            scope2 :: PackScope (Map String [Descr])
+                            scope2 :: PackScope (Map Text [Descr])
                                 =   foldr buildScope (PackScope Map.empty symEmpty) impPackDescrs
                         in return (Just (GenScopeC scope1, GenScopeC scope2))
 --
 -- | Searching of metadata
 --
 
-searchMeta :: Scope -> String -> SearchMode -> IDEM [Descr]
+searchMeta :: Scope -> Text -> SearchMode -> IDEM [Descr]
 searchMeta _ "" _ = return []
 searchMeta (PackageScope False) searchString searchType = do
     packageInfo'    <- getPackageInfo
@@ -613,47 +628,49 @@
                 Just ((GenScopeC (PackScope _ rl)),_) -> return (searchInScope searchType searchString rl
                                         ++  searchInScope searchType searchString s)
 
-searchInScope :: SymbolTable alpha =>  SearchMode -> String -> alpha  -> [Descr]
+searchInScope :: SymbolTable alpha =>  SearchMode -> Text -> alpha  -> [Descr]
 searchInScope (Exact _)  l st      = searchInScopeExact l st
 searchInScope (Prefix True) l st   = (concat . symElems) (searchInScopePrefix l st)
-searchInScope (Prefix False) [] _  = []
+searchInScope (Prefix False) l _ | T.null l = []
 searchInScope (Prefix False) l st  = (concat . symElems) (searchInScopeCaseIns l st "")
 searchInScope (Regex b) l st       = searchRegex l st b
 
 
-searchInScopeExact :: SymbolTable alpha =>  String -> alpha  -> [Descr]
+searchInScopeExact :: SymbolTable alpha =>  Text -> alpha  -> [Descr]
 searchInScopeExact = symLookup
 
-searchInScopePrefix :: SymbolTable alpha   =>  String -> alpha  -> alpha
+searchInScopePrefix :: SymbolTable alpha   =>  Text -> alpha  -> alpha
 searchInScopePrefix searchString symbolTable =
     let (_, exact, mapR)   = symSplitLookup searchString symbolTable
-        (mbL, _, _)        = symSplitLookup (searchString ++ "{") mapR
+        (mbL, _, _)        = symSplitLookup (searchString <> "{") mapR
     in case exact of
             Nothing -> mbL
             Just e  -> symInsert searchString e mbL
 
-searchInScopeCaseIns :: SymbolTable alpha => String -> alpha -> String -> alpha
-searchInScopeCaseIns [] st _                    =  st
-searchInScopeCaseIns (a:l)  st pre | isLower a  =
+searchInScopeCaseIns :: SymbolTable alpha => Text -> alpha -> Text -> alpha
+searchInScopeCaseIns a symbolTable b  = searchInScopeCaseIns' (T.unpack a) symbolTable (T.unpack b)
+  where
+  searchInScopeCaseIns' [] st _                    =  st
+  searchInScopeCaseIns' (a:l)  st pre | isLower a  =
     let s1 = pre ++ [a]
         s2 = pre ++ [toUpper a]
-    in  (symUnion (searchInScopeCaseIns l (searchInScopePrefix s1 st) s1)
-                   (searchInScopeCaseIns l (searchInScopePrefix s2 st) s2))
+    in  (symUnion (searchInScopeCaseIns' l (searchInScopePrefix (T.pack s1) st) s1)
+                   (searchInScopeCaseIns' l (searchInScopePrefix (T.pack s2) st) s2))
                                    | isUpper a  =
     let s1 = pre ++ [a]
         s2 = pre ++ [toLower a]
-    in  (symUnion (searchInScopeCaseIns l (searchInScopePrefix s1 st) s1)
-                   (searchInScopeCaseIns l (searchInScopePrefix s2 st) s2))
+    in  (symUnion (searchInScopeCaseIns' l (searchInScopePrefix (T.pack s1) st) s1)
+                   (searchInScopeCaseIns' l (searchInScopePrefix (T.pack s2) st) s2))
                                     | otherwise =
     let s =  pre ++ [a]
-    in searchInScopeCaseIns l (searchInScopePrefix s st) s
+    in searchInScopeCaseIns' l (searchInScopePrefix (T.pack s) st) s
 
 
-searchRegex :: SymbolTable alpha => String -> alpha  -> Bool -> [Descr]
+searchRegex :: SymbolTable alpha => Text -> alpha  -> Bool -> [Descr]
 searchRegex searchString st caseSense =
     case compileRegex caseSense searchString of
         Left err ->
-            unsafePerformIO $ sysMessage Normal (show err) >> return []
+            unsafePerformIO $ sysMessage Normal (T.pack $ show err) >> return []
         Right regex ->
             filter (\e -> do
                 case execute regex (dscName e) of
@@ -662,7 +679,7 @@
                     _             -> True)
                         (concat (symElems st))
 
-compileRegex :: Bool -> String -> Either String Regex
+compileRegex :: Bool -> Text -> Either String Regex
 compileRegex caseSense searchString =
     let compOption = defaultCompOpt {
                             Regex.caseSensitive = caseSense
@@ -733,39 +750,55 @@
 --
 
 callCollector :: Bool -> Bool -> Bool -> (Bool -> IDEAction) -> IDEAction
-callCollector rebuild sources extract cont = trace "callCollector" $ do
+callCollector rebuild sources extract cont = do
+    liftIO $ infoM "leksah" "callCollector"
     doServerCommand command $ \ res ->
         case res of
-            ServerOK         -> trace "callCollector finished" $ cont True
-            ServerFailed str -> trace str $ cont False
-            _                -> trace "impossible server answer" $ cont False
+            ServerOK         -> do
+                liftIO $ infoM "leksah" "callCollector finished"
+                cont True
+            ServerFailed str -> do
+                liftIO $ infoM "leksah" (T.unpack str)
+                cont False
+            _                -> do
+                liftIO $ infoM "leksah" "impossible server answer"
+                cont False
     where command = SystemCommand {
             scRebuild = rebuild,
             scSources = sources,
             scExtract = extract}
 
-callCollectorWorkspace :: Bool -> FilePath -> PackageIdentifier -> [(String,FilePath)] ->
+callCollectorWorkspace :: Bool -> FilePath -> PackageIdentifier -> [(Text,FilePath)] ->
     (Bool -> IDEAction) -> IDEAction
-callCollectorWorkspace rebuild fp  pi modList cont = trace "callCollectorWorkspace" $
+callCollectorWorkspace rebuild fp  pi modList cont = do
+    liftIO $ infoM "leksah" "callCollectorWorkspace"
     if null modList
-        then trace "callCollectorWorkspace: Nothing to do" $ cont True
+        then do
+            liftIO $ infoM "leksah" "callCollectorWorkspace: Nothing to do"
+            cont True
         else do
             doServerCommand command  $ \ res ->
                 case res of
-                    ServerOK         -> trace "callCollectorWorkspace finished" $ cont True
-                    ServerFailed str -> trace str $ cont False
-                    _                -> trace "impossible server answer" $ cont False
+                    ServerOK         -> do
+                        liftIO $ infoM "leksah" "callCollectorWorkspace finished"
+                        cont True
+                    ServerFailed str -> do
+                        liftIO $ infoM "leksah" (T.unpack str)
+                        cont False
+                    _                -> do
+                        liftIO $ infoM "leksah" "impossible server answer"
+                        cont False
     where command = WorkspaceCommand {
-            wcRebuild = rebuild,
-            wcPackage = pi,
-            wcPath    = fp,
-            wcModList = modList}
+            wcRebuild     = rebuild,
+            wcPackage     = pi,
+            wcPath        = fp,
+            wcModList     = modList}
 
 -- ---------------------------------------------------------------------
 -- Additions for completion
 --
 
-keywords :: [String]
+keywords :: [Text]
 keywords = [
         "as"
     ,   "case"
@@ -807,22 +840,18 @@
 
 extensionDescrs :: [Descr]
 extensionDescrs =  map (\ext -> Real $ RealDescr
-                                    ("X" ++ show ext)
+                                    (T.pack $ "X" ++ show ext)
                                     Nothing
                                     Nothing
                                     Nothing
                                     (Just (BS.pack " Haskell language extension"))
                                     ExtensionDescr
                                     True)
-#if MIN_VERSION_Cabal(1,16,0)
                                 ([minBound..maxBound]::[KnownExtension])
-#else
-                                knownExtensions
-#endif
 
 moduleNameDescrs :: PackageDescr -> [Descr]
 moduleNameDescrs pd = map (\md -> Real $ RealDescr
-                                    ((display . modu . mdModuleId) md)
+                                    (T.pack . display . modu $ mdModuleId md)
                                     Nothing
                                     (Just (mdModuleId md))
                                     Nothing
diff --git a/src/IDE/NotebookFlipper.hs b/src/IDE/NotebookFlipper.hs
--- a/src/IDE/NotebookFlipper.hs
+++ b/src/IDE/NotebookFlipper.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.NotebookFlipper
diff --git a/src/IDE/OSX.hs b/src/IDE/OSX.hs
--- a/src/IDE/OSX.hs
+++ b/src/IDE/OSX.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.OSX
@@ -29,24 +30,25 @@
 import Control.Monad.Reader.Class (ask)
 import Graphics.UI.Gtk.OSX
 import IDE.Command (canQuit)
+import Data.Text (Text)
 
 updateMenu :: Application -> UIManager -> IDEM ()
 updateMenu app uiManager = do
     ideR <- ask
     liftIO $ do
-        mbMenu   <- uiManagerGetWidget uiManager "/ui/menubar"
+        mbMenu   <- uiManagerGetWidget uiManager ("/ui/menubar" :: Text)
         case mbMenu of
             Just menu -> do
                 widgetHide menu
                 applicationSetMenuBar app (castToMenuShell menu)
             Nothing   -> return ()
 
-        mbQuit   <- uiManagerGetWidget uiManager "/ui/menubar/_File/_Quit"
+        mbQuit   <- uiManagerGetWidget uiManager ("/ui/menubar/_File/_Quit" :: Text)
         case mbQuit of
             Just quit -> widgetHide quit
             Nothing   -> return ()
 
-        mbAbout   <- uiManagerGetWidget uiManager "/ui/menubar/_Help/_About"
+        mbAbout   <- uiManagerGetWidget uiManager ("/ui/menubar/_Help/_About" :: Text)
         case mbAbout of
             Just about -> do
                 applicationInsertAppMenuItem app (castToMenuItem about) 0
@@ -54,7 +56,7 @@
                 applicationInsertAppMenuItem app sep 1
             Nothing   -> return ()
 
-        mbPrefs   <- uiManagerGetWidget uiManager "/ui/menubar/_Configuration/Edit general Preferences"
+        mbPrefs   <- uiManagerGetWidget uiManager ("/ui/menubar/_Configuration/Edit general Preferences" :: Text)
         case mbPrefs of
             Just prefs -> do
                 applicationInsertAppMenuItem app (castToMenuItem prefs) 2
diff --git a/src/IDE/Package.hs b/src/IDE/Package.hs
--- a/src/IDE/Package.hs
+++ b/src/IDE/Package.hs
@@ -92,7 +92,6 @@
 import Distribution.Text (display)
 import IDE.Utils.FileUtils(getConfigFilePathForLoad)
 import IDE.LogRef
-import MyMissing (replace)
 import Distribution.ModuleName (ModuleName(..))
 import Data.List (isInfixOf, nub, foldl', delete)
 import qualified System.IO.UTF8 as UTF8  (readFile)
@@ -100,12 +99,11 @@
 import qualified Data.Set as  Set (fromList)
 import qualified Data.Map as  Map (empty, fromList)
 import System.Exit (ExitCode(..))
-import Control.Applicative ((<$>))
+import Control.Applicative ((<$>), (<*>))
 import IDE.Utils.Tool (executeGhciCommand, getProcessExitCode, interruptProcessGroupOf,
     ProcessHandle)
-import qualified Data.Conduit as C (Sink)
+import qualified Data.Conduit as C (Sink, ZipSink(..), getZipSink)
 import qualified Data.Conduit.List as CL (foldM, fold, consume)
-import qualified Data.Conduit.Util as CU (zipSinks)
 import Data.Conduit (($$))
 import Control.Monad.Trans.Reader (ask)
 import Control.Monad.IO.Class (MonadIO(..))
@@ -117,13 +115,21 @@
 import IDE.Pane.WebKit.Documentation
        (getDocumentation, loadDoc, reloadDoc)
 import IDE.Pane.WebKit.Output (loadOutputUri, getOutputPane)
-import Text.Printf (printf)
 import System.Log.Logger (debugM)
 import System.Process.Vado (getMountPoint, vado, readSettings)
-import qualified Data.Text as T (pack, unpack, isInfixOf)
+import qualified Data.Text as T
+       (replace, unwords, takeWhile, pack, unpack, isInfixOf)
 import IDE.Utils.ExternalTool (runExternalTool', runExternalTool, isRunning, interruptBuild)
 import Text.PrinterParser (writeFields)
+import Data.Text (Text)
+import Data.Monoid ((<>))
+import qualified Data.Text.IO as T (readFile)
+import qualified Text.Printf as S (printf)
+import Text.Printf (PrintfType)
 
+printf :: PrintfType r => Text -> r
+printf = S.printf . T.unpack
+
 -- | Get the last item
 sinkLast = CL.fold (\_ a -> Just a) Nothing
 
@@ -138,7 +144,7 @@
 myTestModules pd = concatMap (moduleInfo testBuildInfo (otherModules . testBuildInfo)) (testSuites pd)
 myBenchmarkModules pd = concatMap (moduleInfo benchmarkBuildInfo (otherModules . benchmarkBuildInfo)) (benchmarks pd)
 
-activatePackage :: Maybe FilePath -> Maybe IDEPackage -> Maybe String -> IDEM ()
+activatePackage :: Maybe FilePath -> Maybe IDEPackage -> Maybe Text -> IDEM ()
 activatePackage mbPath mbPack mbExe = do
     liftIO $ debugM "leksah" "activatePackage"
     oldActivePack <- readIDE activePack
@@ -154,9 +160,9 @@
                     Nothing -> ""
                     Just ws -> wsName ws
         txt = case (mbPath, mbPack) of
-                    (_, Just pack) -> wsStr ++ " > " ++ packageIdentifierToString (ipdPackageId pack)
-                    (Just path, _) -> wsStr ++ " > " ++ takeFileName path
-                    _ -> wsStr ++ ":"
+                    (_, Just pack) -> wsStr <> " > " <> packageIdentifierToString (ipdPackageId pack)
+                    (Just path, _) -> wsStr <> " > " <> T.pack (takeFileName path)
+                    _ -> wsStr <> ":"
     triggerEventIDE (StatusbarChanged [CompartmentPackage txt])
     return ()
 
@@ -179,7 +185,7 @@
                             (cabalCommand prefs)
                             (["configure"] ++ (ipdConfigFlags package))
                             dir $ do
-        (mbLastOutput, _) <- CU.zipSinks sinkLast (logOutput logLaunch)
+        mbLastOutput <- C.getZipSink $ const <$> C.ZipSink sinkLast <*> C.ZipSink (logOutput logLaunch)
         lift $ do
             mbPack <- idePackageFromPath (logOutput logLaunch) (ipdCabalFile package)
             case mbPack of
@@ -204,8 +210,10 @@
                 ++ ipdBuildFlags package
                 ++ (if runTests then ipdTestFlags package else []))
     runExternalTool' (__ "Building") (cabalCommand prefs) args dir $ do
-        (mbLastOutput, (isConfigErr, _)) <- CU.zipSinks sinkLast $ CU.zipSinks isConfigError $
-            logOutputForBuild package backgroundBuild jumpToWarnings
+        (mbLastOutput, isConfigErr, _) <- C.getZipSink $ (,,)
+            <$> C.ZipSink sinkLast
+            <*> C.ZipSink isConfigError
+            <*> (C.ZipSink $ logOutputForBuild package backgroundBuild jumpToWarnings)
         lift $ do
             errs <- readIDE errorRefs
             if shallConfigure && isConfigErr
@@ -221,9 +229,9 @@
     where
     isCErr (ToolError str) = str1 `T.isInfixOf` str || str2 `T.isInfixOf` str || str3 `T.isInfixOf` str
     isCErr _ = False
-    str1 = T.pack (__ "Run the 'configure' command first")
-    str2 = T.pack (__ "please re-configure")
-    str3 = T.pack (__ "cannot satisfy -package-id")
+    str1 = __ "Run the 'configure' command first"
+    str2 = __ "please re-configure"
+    str3 = __ "cannot satisfy -package-id"
 
 buildPackage :: Bool -> Bool -> Bool -> Bool -> IDEPackage -> (Bool -> IDEAction) -> IDEAction
 buildPackage backgroundBuild runTests jumpToWarnings withoutLinking package continuation = catchIDE (do
@@ -248,7 +256,7 @@
                         when f $ do
                             mbURI <- readIDE autoURI
                             case mbURI of
-                                Just uri -> postSyncIDE $ loadOutputUri uri
+                                Just uri -> postSyncIDE . loadOutputUri $ T.unpack uri
                                 Nothing  -> return ()
                         continuation f
         Just debug@(_, ghci) -> do
@@ -264,7 +272,7 @@
                         liftIO . postGUISync $ reflectIDE cmd ideR
                         lift $ continuation True
     )
-    (\(e :: SomeException) -> sysMessage Normal (show e))
+    (\(e :: SomeException) -> sysMessage Normal (T.pack $ show e))
 
 packageDoc :: PackageAction
 packageDoc = do
@@ -278,8 +286,8 @@
         let dir = ipdBuildDir package
         runExternalTool' (__ "Documenting") (cabalCommand prefs) (["haddock"]
             ++ (ipdHaddockFlags package)) dir $ do
-                (mbLastOutput, _) <- CU.zipSinks sinkLast $
-                    logOutputForBuild package backgroundBuild jumpToWarnings
+                mbLastOutput <- C.getZipSink $ const <$> C.ZipSink sinkLast <*> (C.ZipSink $
+                    logOutputForBuild package backgroundBuild jumpToWarnings)
                 lift $ reloadDoc
                 lift $ continuation (mbLastOutput == Just (ToolExit ExitSuccess)))
         (\(e :: SomeException) -> putStrLn (show e))
@@ -300,7 +308,7 @@
                     (cabalCommand prefs)
                     ["clean"]
                     dir $ do
-        (mbLastOutput, _) <- CU.zipSinks sinkLast (logOutput logLaunch)
+        mbLastOutput <- C.getZipSink $ const <$> C.ZipSink sinkLast <*> C.ZipSink (logOutput logLaunch)
         lift $ continuation (mbLastOutput == Just (ToolExit ExitSuccess))
 
 packageCopy :: PackageAction
@@ -320,7 +328,7 @@
                     let dir = ipdBuildDir package
                     runExternalTool' (__ "Copying")
                                     (cabalCommand prefs)
-                                    (["copy"] ++ ["--destdir=" ++ fp])
+                                    (["copy"] ++ ["--destdir=" <> T.pack fp])
                                     dir
                                     (logOutput logLaunch))
             (\(e :: SomeException) -> putStrLn (show e))
@@ -353,7 +361,7 @@
         let dir = ipdBuildDir package
         runExternalTool' (__ "Copying") (cabalCommand prefs) (["copy"]
             ++ (ipdInstallFlags package)) dir $ do
-                (mbLastOutput, _) <- CU.zipSinks sinkLast (logOutput logLaunch)
+                mbLastOutput <- C.getZipSink $ (const <$> C.ZipSink sinkLast) <*> C.ZipSink (logOutput logLaunch)
                 lift $ continuation (mbLastOutput == Just (ToolExit ExitSuccess)))
         (\(e :: SomeException) -> putStrLn (show e))
 
@@ -361,14 +369,14 @@
 packageRun = ask >>= (liftIDE . packageRun' True)
 
 packageRun' :: Bool -> IDEPackage -> IDEAction
-packageRun' addFlagIfMissing package = do
-    if addFlagIfMissing && "--ghcjs" `elem` ipdConfigFlags package && not ("--ghcjs-option=--native-executables" `elem` ipdConfigFlags package)
+packageRun' removeGhcjsFlagIfPresent package = do
+    if removeGhcjsFlagIfPresent && "--ghcjs" `elem` ipdConfigFlags package
         then do
             window <- liftIDE $ getMainWindow
             resp <- liftIO $ do
                 md <- messageDialogNew (Just window) [] MessageQuestion ButtonsCancel
-                        (__ "Package is configured to use GHCJS.  Would you like to add --ghcjs-option=--native-executables to the configure flags and rebuild?")
-                dialogAddButton md (__ "Add _GHCJS Native Executables") (ResponseUser 1)
+                        (__ "Package is configured to use GHCJS.  Would you like to remove --ghcjs from the configure flags and rebuild?")
+                dialogAddButton md (__ "Use _GHC") (ResponseUser 1)
                 dialogSetDefaultResponse md (ResponseUser 1)
                 set md [ windowWindowPosition := WinPosCenterOnParent ]
                 resp <- dialogRun md
@@ -376,7 +384,7 @@
                 return resp
             case resp of
                 ResponseUser 1 -> do
-                    let packWithNewFlags = package { ipdConfigFlags = ["--ghcjs-option=--native-executables"] ++ ipdConfigFlags package }
+                    let packWithNewFlags = package { ipdConfigFlags = filter (/="--ghcjs") $ ipdConfigFlags package }
                     changePackage packWithNewFlags
                     liftIO $ writeFlags (dropExtension (ipdCabalFile packWithNewFlags) ++ leksahFlagFileExtension) packWithNewFlags
                     packageConfig' packWithNewFlags $ \ ok -> when ok $ do
@@ -388,18 +396,18 @@
             pd <- liftIO $ readPackageDescription normal (ipdCabalFile package) >>= return . flattenPackageDescription
             mbExe <- readIDE activeExe
             let exe = take 1 . filter (isActiveExe mbExe) $ executables pd
-            let defaultLogName = display . pkgName $ ipdPackageId package
-                logName = fromMaybe defaultLogName . listToMaybe $ map exeName exe
+            let defaultLogName = T.pack . display . pkgName $ ipdPackageId package
+                logName = fromMaybe defaultLogName . listToMaybe $ map (T.pack . exeName) exe
             (logLaunch,logName) <- buildLogLaunchByName logName
             case maybeDebug of
                 Nothing -> do
                     let dir = ipdBuildDir package
                     IDE.Package.runPackage (addLogLaunchData logName logLaunch)
-                                           (printf (__ "Running %s") logName)
+                                           (T.pack $ printf (__ "Running %s") (T.unpack logName))
                                            "cabal"
                                            (concat [["run"]
                                                 , ipdBuildFlags package
-                                                , map exeName exe
+                                                , map (T.pack . exeName) exe
                                                 , ["--"]
                                                 , ipdExeFlags package])
                                            dir
@@ -409,13 +417,14 @@
                     runDebug (do
                         case exe of
                             [Executable name mainFilePath _] -> do
-                                executeDebugCommand (":module *" ++ (map (\c -> if c == '/' then '.' else c) (takeWhile (/= '.') mainFilePath))) (logOutput logLaunch)
+                                executeDebugCommand (":module *" <> T.pack (map (\c -> if c == '/' then '.' else c) (takeWhile (/= '.') mainFilePath)))
+                                                    (logOutput logLaunch)
                             _ -> return ()
-                        executeDebugCommand (":main " ++ (unwords (ipdExeFlags package))) (logOutput logLaunch))
+                        executeDebugCommand (":main " <> T.unwords (ipdExeFlags package)) (logOutput logLaunch))
                         debug)
             (\(e :: SomeException) -> putStrLn (show e))
   where
-    isActiveExe selected (Executable name _ _) = selected == Just name
+    isActiveExe selected (Executable name _ _) = selected == Just (T.pack name)
 
 packageRunJavaScript :: PackageAction
 packageRunJavaScript = ask >>= (liftIDE . packageRunJavaScript' True)
@@ -448,8 +457,8 @@
                 pd <- liftIO $ readPackageDescription normal (ipdCabalFile package) >>= return . flattenPackageDescription
                 mbExe <- readIDE activeExe
                 let exe = take 1 . filter (isActiveExe mbExe) $ executables pd
-                let defaultLogName = display . pkgName $ ipdPackageId package
-                    logName = fromMaybe defaultLogName . listToMaybe $ map exeName exe
+                let defaultLogName = T.pack . display . pkgName $ ipdPackageId package
+                    logName = fromMaybe defaultLogName . listToMaybe $ map (T.pack . exeName) exe
                 (logLaunch,logName) <- buildLogLaunchByName logName
                 let dir = ipdBuildDir package
                 prefs <- readIDE prefs
@@ -469,7 +478,7 @@
                     _ -> return ())
                 (\(e :: SomeException) -> putStrLn (show e))
   where
-    isActiveExe selected (Executable name _ _) = selected == Just name
+    isActiveExe selected (Executable name _ _) = selected == Just (T.pack name)
 
 packageRegister :: PackageAction
 packageRegister = do
@@ -487,7 +496,7 @@
             let dir = ipdBuildDir package
             runExternalTool' (__ "Registering") (cabalCommand prefs) (["register"]
                 ++ (ipdRegisterFlags package)) dir $ do
-                    (mbLastOutput, _) <- CU.zipSinks sinkLast (logOutput logLaunch)
+                    mbLastOutput <- C.getZipSink $ (const <$> C.ZipSink sinkLast) <*> C.ZipSink (logOutput logLaunch)
                     lift $ continuation (mbLastOutput == Just (ToolExit ExitSuccess)))
             (\(e :: SomeException) -> putStrLn (show e))
         else continuation True
@@ -508,8 +517,10 @@
             let dir = ipdBuildDir package
             runExternalTool' (__ "Testing") (cabalCommand prefs) (["test"]
                 ++ ipdBuildFlags package ++ ipdTestFlags package) dir $ do
-                    (mbLastOutput, (isConfigErr, _)) <- CU.zipSinks sinkLast $ CU.zipSinks isConfigError $
-                        logOutputForBuild package False True
+                    (mbLastOutput, isConfigErr, _) <- C.getZipSink $ (,,)
+                        <$> C.ZipSink sinkLast
+                        <*> C.ZipSink isConfigError
+                        <*> (C.ZipSink $ logOutputForBuild package False True)
                     lift $ do
                         errs <- readIDE errorRefs
                         if shallConfigure && isConfigErr
@@ -549,19 +560,19 @@
                         </> "index.html"
             dir = ipdBuildDir package
 #ifdef WEBKITGTK
-        loadDoc ("file:///" ++ dir </> path)
+        loadDoc . T.pack $ "file:///" ++ dir </> path
         getDocumentation Nothing  >>= \ p -> displayPane p False
 #else
-        openBrowser path
+        openBrowser $ T.pack path
 #endif
       `catchIDE`
         (\(e :: SomeException) -> putStrLn (show e))
 
 
 runPackage ::  (ProcessHandle -> IDEAction)
-            -> String
+            -> Text
             -> FilePath
-            -> [String]
+            -> [Text]
             -> FilePath
             -> C.Sink ToolOutput IDEM ()
             -> IDEAction
@@ -585,29 +596,31 @@
                 pd <- readPackageDescription normal (ipdCabalFile p)
                 return (Just (flattenPackageDescription pd,ipdCabalFile p)))
                     (\(e :: SomeException) -> do
-                        reflectIDE (ideMessage Normal ((__ "Can't load package ") ++(show e))) ideR
+                        reflectIDE (ideMessage Normal ((__ "Can't load package ") <> T.pack (show e))) ideR
                         return Nothing))
 
-getEmptyModuleTemplate :: PackageDescription -> String -> IO String
+getEmptyModuleTemplate :: PackageDescription -> Text -> IO Text
 getEmptyModuleTemplate pd modName = getModuleTemplate "module" pd modName "" ""
 
-getModuleTemplate :: String -> PackageDescription -> String -> String -> String -> IO String
-getModuleTemplate template pd modName exports body = catch (do
+getModuleTemplate :: FilePath -> PackageDescription -> Text -> Text -> Text -> IO Text
+getModuleTemplate templateName pd modName exports body = catch (do
     dataDir  <- getDataDir
-    filePath <- getConfigFilePathForLoad (template ++ leksahTemplateFileExtension) Nothing dataDir
-    template <- UTF8.readFile filePath
-    return (foldl' (\ a (from, to) -> replace from to a) template
-        [   ("@License@"      , (display . license) pd)
-        ,   ("@Maintainer@"   , maintainer pd)
-        ,   ("@Stability@"    , stability pd)
+    filePath <- getConfigFilePathForLoad (templateName <> leksahTemplateFileExtension) Nothing dataDir
+    template <- T.readFile filePath
+    return (foldl' (\ a (from, to) -> T.replace from to a) template
+        [   ("@License@"      , (T.pack . display . license) pd)
+        ,   ("@Maintainer@"   , T.pack $ maintainer pd)
+        ,   ("@Stability@"    , T.pack $ stability pd)
         ,   ("@Portability@"  , "")
-        ,   ("@Copyright@"    , copyright pd)
+        ,   ("@Copyright@"    , T.pack $ copyright pd)
         ,   ("@ModuleName@"   , modName)
         ,   ("@ModuleExports@", exports)
         ,   ("@ModuleBody@"   , body)]))
-                    (\ (e :: SomeException) -> sysMessage Normal (printf (__ "Couldn't read template file: %s") (show e)) >> return "")
+                    (\ (e :: SomeException) -> do
+                        sysMessage Normal . T.pack $ printf (__ "Couldn't read template file: %s") (show e)
+                        return "")
 
-data ModuleLocation = LibExposedMod | LibOtherMod | ExeOrTestMod String
+data ModuleLocation = LibExposedMod | LibOtherMod | ExeOrTestMod Text
 
 addModuleToPackageDescr :: ModuleName -> [ModuleLocation] -> PackageAction
 addModuleToPackageDescr moduleName locations = do
@@ -617,14 +630,14 @@
         let npd = trace (show gpd) foldr addModule gpd locations
         writeGenericPackageDescription (ipdCabalFile p) npd)
            (\(e :: SomeException) -> do
-            reflectIDE (ideMessage Normal ((__ "Can't update package ") ++ show e)) ideR
+            reflectIDE (ideMessage Normal ((__ "Can't update package ") <> T.pack (show e))) ideR
             return ()))
   where
     addModule LibExposedMod gpd@GenericPackageDescription{condLibrary = Just lib} =
         gpd {condLibrary = Just (addModToLib moduleName lib)}
     addModule LibOtherMod gpd@GenericPackageDescription{condLibrary = Just lib} =
         gpd {condLibrary = Just (addModToBuildInfoLib moduleName lib)}
-    addModule (ExeOrTestMod name) gpd = gpd {
+    addModule (ExeOrTestMod name') gpd = let name = T.unpack name' in gpd {
           condExecutables = map (addModToBuildInfoExe  name moduleName) (condExecutables gpd)
         , condTestSuites  = map (addModToBuildInfoTest name moduleName) (condTestSuites gpd)
         }
@@ -680,7 +693,7 @@
                                                 (condExecutables gpd)}
         writeGenericPackageDescription (ipdCabalFile p) npd)
            (\(e :: SomeException) -> do
-            reflectIDE (ideMessage Normal ((__ "Can't update package ") ++ show e)) ideR
+            reflectIDE (ideMessage Normal ((__ "Can't update package ") <> T.pack (show e))) ideR
             return ()))
 
 delModFromLib :: ModuleName -> CondTree ConfVar [Dependency] Library ->
@@ -723,22 +736,22 @@
 -- | * Debug code that needs to use the package
 --
 
-interactiveFlag :: String -> Bool -> String
-interactiveFlag name f = (if f then "-f" else "-fno-") ++ name
+interactiveFlag :: Text -> Bool -> Text
+interactiveFlag name f = (if f then "-f" else "-fno-") <> name
 
-printEvldWithShowFlag :: Bool -> String
+printEvldWithShowFlag :: Bool -> Text
 printEvldWithShowFlag = interactiveFlag "print-evld-with-show"
 
-breakOnExceptionFlag :: Bool -> String
+breakOnExceptionFlag :: Bool -> Text
 breakOnExceptionFlag = interactiveFlag "break-on-exception"
 
-breakOnErrorFlag :: Bool -> String
+breakOnErrorFlag :: Bool -> Text
 breakOnErrorFlag = interactiveFlag "break-on-error"
 
-printBindResultFlag :: Bool -> String
+printBindResultFlag :: Bool -> Text
 printBindResultFlag = interactiveFlag "print-bind-result"
 
-interactiveFlags :: Prefs -> [String]
+interactiveFlags :: Prefs -> [Text]
 interactiveFlags prefs =
     (printEvldWithShowFlag $ printEvldWithShow prefs)
     : (breakOnExceptionFlag $ breakOnException prefs)
@@ -823,7 +836,7 @@
         _ -> do
             return ()
 
-executeDebugCommand :: String -> (C.Sink ToolOutput IDEM ()) -> DebugAction
+executeDebugCommand :: Text -> (C.Sink ToolOutput IDEM ()) -> DebugAction
 executeDebugCommand command handler = do
     (_, ghci) <- ask
     lift $ do
@@ -851,7 +864,7 @@
         pd <- readPackageDescription normal ipdCabalFile
         return (Just (flattenPackageDescription pd)))
             (\ (e  :: SomeException) -> do
-                reflectIDE (ideMessage Normal ((__ "Can't activate package ") ++(show e))) ideR
+                reflectIDE (ideMessage Normal ((__ "Can't activate package ") <> T.pack (show e))) ideR
                 return Nothing))
     case mbPackageD of
         Nothing       -> return Nothing
@@ -866,12 +879,12 @@
                 ipdSrcDirs          = case (nub $ concatMap hsSourceDirs (allBuildInfo' packageD)) of
                                             [] -> [".","src"]
                                             l -> l
-                ipdExes             = [ exeName e | e <- executables packageD
+                ipdExes             = [ T.pack $ exeName e | e <- executables packageD
                                           , buildable (buildInfo e) ]
                 ipdExtensions       = nub $ concatMap oldExtensions (allBuildInfo' packageD)
-                ipdTests            = [ testName t | t <- testSuites packageD
+                ipdTests            = [ T.pack $ testName t | t <- testSuites packageD
                                           , buildable (testBuildInfo t) ]
-                ipdBenchmarks       = [ benchmarkName b | b <- benchmarks packageD
+                ipdBenchmarks       = [ T.pack $ benchmarkName b | b <- benchmarks packageD
                                           , buildable (benchmarkBuildInfo b) ]
                 ipdPackageId        = package packageD
                 ipdDepends          = buildDepends packageD
diff --git a/src/IDE/Pane/Breakpoints.hs b/src/IDE/Pane/Breakpoints.hs
--- a/src/IDE/Pane/Breakpoints.hs
+++ b/src/IDE/Pane/Breakpoints.hs
@@ -1,5 +1,8 @@
-{-# LANGUAGE FlexibleInstances, TypeSynonymInstances,
-   MultiParamTypeClasses, DeriveDataTypeable #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Breakpoints
@@ -36,7 +39,7 @@
 import Data.List (elemIndex)
 import Control.Monad.IO.Class (MonadIO(..))
 import IDE.Utils.GUIUtils (treeViewContextMenu, __)
-import qualified Data.Text as T (unpack)
+import qualified Data.Text as T (words, unpack)
 
 
 -- | A breakpoints pane description
@@ -88,7 +91,7 @@
         treeViewAppendColumn treeView colB
         cellLayoutPackStart colB rendererB False
         cellLayoutSetAttributes colB rendererB breakpoints
-            $ \row -> [ cellText := T.unpack $ refDescription row]
+            $ \row -> [ cellText := refDescription row]
 
         treeViewSetHeadersVisible treeView True
         selB <- treeViewGetSelection treeView
@@ -183,7 +186,7 @@
 deleteBreakpoint :: LogRef -> IDEAction
 deleteBreakpoint logRef =
     case logRefType logRef of
-        BreakpointRef -> debugDeleteBreakpoint (words (T.unpack $ refDescription logRef) !! 1) logRef
+        BreakpointRef -> debugDeleteBreakpoint (T.words (refDescription logRef) !! 1) logRef
         _   -> sysMessage Normal (__ "Debugger>>deleteBreakpoint: Not a breakpoint")
 
 
diff --git a/src/IDE/Pane/Errors.hs b/src/IDE/Pane/Errors.hs
--- a/src/IDE/Pane/Errors.hs
+++ b/src/IDE/Pane/Errors.hs
@@ -88,7 +88,7 @@
         $ \row -> [cellText := if index row == 0 then showSourceSpan (logRef row) else "",
                    cellTextForeground := if logRefType (logRef row) == WarningRef
                                             then "green"
-                                            else "red" ]
+                                            else "red"::Text ]
     rendererB    <- cellRendererTextNew
     colB         <- treeViewColumnNew
     treeViewColumnSetTitle colB (__ "Description")
@@ -98,7 +98,7 @@
     treeViewAppendColumn treeView colB
     cellLayoutPackStart colB rendererB False
     cellLayoutSetAttributes colB rendererB errorStore
-        $ \row -> [ cellText := T.unpack $ text row]
+        $ \row -> [ cellText := text row]
 
     treeViewSetHeadersVisible treeView True
     selB <- treeViewGetSelection treeView
diff --git a/src/IDE/Pane/Files.hs b/src/IDE/Pane/Files.hs
--- a/src/IDE/Pane/Files.hs
+++ b/src/IDE/Pane/Files.hs
@@ -1,5 +1,10 @@
-{-# LANGUAGE FlexibleInstances, DeriveDataTypeable, MultiParamTypeClasses,
-             TypeSynonymInstances, RecordWildCards,  ScopedTypeVariables #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Files
@@ -45,7 +50,7 @@
         workspace, readIDE, IDEAction, ideMessage, reflectIDE, reifyIDE,
         IDEM, IDEPackage, ipdSandboxSources)
 import IDE.Pane.SourceBuffer
-    (goToSourceDefinition)
+    (goToSourceDefinition')
 import Control.Applicative ((<$>))
 import System.FilePath ((</>), takeFileName, dropFileName)
 import Distribution.Package (PackageIdentifier(..))
@@ -63,6 +68,9 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import IDE.Utils.GUIUtils (__)
 import Control.Exception (catch)
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
+import Data.Monoid ((<>))
 
 data FileRecord =
     FileRecord FilePath
@@ -70,10 +78,10 @@
   | PackageRecord IDEPackage
   | PlaceHolder deriving(Eq)
 
-file :: FileRecord -> String
-file (FileRecord f) = takeFileName f
-file (DirRecord f) = takeFileName f
-file (PackageRecord p) = packageIdentifierToString (ipdPackageId p) ++ " " ++ ipdBuildDir p
+file :: FileRecord -> Text
+file (FileRecord f) = T.pack $ takeFileName f
+file (DirRecord f) = T.pack $ takeFileName f
+file (PackageRecord p) = packageIdentifierToString (ipdPackageId p) <> " " <> T.pack (ipdBuildDir p)
 file PlaceHolder = ""
 
 -- | A files pane description
@@ -143,7 +151,7 @@
             record <- treeStoreGetValue fileStore path
             reflectIDE (
                 case record of
-                    FileRecord f    -> void (goToSourceDefinition f (Just $ Location 1 0 1 0))
+                    FileRecord f    -> void (goToSourceDefinition' f (Location "" 1 0 1 0))
                     DirRecord f     -> liftIO $ refreshDir fileStore path f
                     PackageRecord p -> liftIO $ refreshPackage fileStore path p
                     _               -> ideMessage Normal (__ "Unexpected Activation in Files Pane")) ideR
diff --git a/src/IDE/Pane/Grep.hs b/src/IDE/Pane/Grep.hs
--- a/src/IDE/Pane/Grep.hs
+++ b/src/IDE/Pane/Grep.hs
@@ -1,10 +1,11 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Grep
@@ -60,14 +61,15 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import IDE.Utils.GUIUtils (__)
 import System.Directory (getDirectoryContents)
-import qualified Data.Text as T (unpack)
+import qualified Data.Text as T (pack, take, unpack)
 import System.Log.Logger (debugM)
 import Control.Exception (SomeException, catch)
+import Data.Text (Text)
 
 data GrepRecord = GrepRecord {
             file        :: FilePath
         ,   line        :: Int
-        ,   context     :: String
+        ,   context     :: Text
         ,   parDir      :: Maybe FilePath
         }
 
@@ -115,7 +117,7 @@
         treeViewAppendColumn treeView col1
         cellLayoutPackStart col1 renderer1 True
         cellLayoutSetAttributes col1 renderer1 grepStore
-            $ \row -> [ cellText := file row]
+            $ \row -> [ cellText := T.pack $ file row]
 
         renderer2   <- cellRendererTextNew
         col2        <- treeViewColumnNew
@@ -126,7 +128,7 @@
         treeViewAppendColumn treeView col2
         cellLayoutPackStart col2 renderer2 True
         cellLayoutSetAttributes col2 renderer2 grepStore
-            $ \row -> [ cellText := show $ line row]
+            $ \row -> [ cellText := T.pack $ show $ line row]
 
         renderer3    <- cellRendererTextNew
         col3         <- treeViewColumnNew
@@ -137,7 +139,7 @@
         treeViewAppendColumn treeView col3
         cellLayoutPackStart col3 renderer3 True
         cellLayoutSetAttributes col3 renderer3 grepStore
-            $ \row -> [ cellText := take 2048 $ context row]
+            $ \row -> [ cellText := T.take 2048 $ context row]
 
 
         treeViewSetHeadersVisible treeView True
@@ -160,7 +162,7 @@
                     Just record -> reflectIDE (do
                         case record of
                             GrepRecord {file=f, line=l, parDir=Just pp} ->
-                                (goToSourceDefinition (pp </> f) $ Just $ Location l 0 l 0)
+                                (goToSourceDefinition pp $ Location f l 0 l 0)
                                     ?>>= (\(IDEBuffer {sourceView = sv}) -> when focus $ grabFocus sv)
                             _ -> return ()) ideR
                     Nothing -> return ()
@@ -197,7 +199,7 @@
         char ':'
         line <- int
         char ':'
-        context <- many anyChar
+        context <- T.pack <$> many anyChar
         let parDir = Nothing
         return $ GrepRecord {..}
     <?> "grepLineParser")
@@ -222,7 +224,7 @@
         _   ->  return Nothing
 
 --TODO srp use default loglaunch probably
-grepWorkspace :: String -> Bool -> WorkspaceAction
+grepWorkspace :: Text -> Bool -> WorkspaceAction
 grepWorkspace "" caseSensitive = return ()
 grepWorkspace regexString caseSensitive = do
     ws <- ask
@@ -233,7 +235,7 @@
     lift $ grepDirectories regexString caseSensitive $
             map (\p -> (dropFileName $ ipdCabalFile p)) $ packages
 
-grepDirectories :: String -> Bool -> [FilePath] -> IDEAction
+grepDirectories :: Text -> Bool -> [FilePath] -> IDEAction
 grepDirectories regexString caseSensitive dirs = do
     grep <- getGrep Nothing
     let store = grepStore grep
@@ -261,7 +263,7 @@
                                 "--exclude-dir=_darcs",
                                 "--exclude-dir=.git",
 #endif
-                                regexString] ++ subDirs) (Just dir)
+                                regexString] ++ map T.pack subDirs) (Just dir)
                         reflectIDE (do
                             output $$ do
                                 let max = 1000
@@ -283,7 +285,7 @@
             nooneWaiting <- isEmptyMVar (waitingGrep grep)
             when nooneWaiting $ postGUISync $ do
                 nDir <- treeModelIterNChildren store Nothing
-                treeStoreInsert store [] nDir $ GrepRecord (__ "Search Complete") totalFound "" Nothing
+                treeStoreInsert store [] nDir $ GrepRecord (T.unpack $ __ "Search Complete") totalFound "" Nothing
 
             takeMVar (activeGrep grep) >> return ()
     return ()
diff --git a/src/IDE/Pane/HLint.hs b/src/IDE/Pane/HLint.hs
--- a/src/IDE/Pane/HLint.hs
+++ b/src/IDE/Pane/HLint.hs
@@ -1,6 +1,9 @@
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE FlexibleInstances, DeriveDataTypeable, MultiParamTypeClasses,
-             TypeSynonymInstances, RecordWildCards #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.HLint
@@ -34,7 +37,7 @@
 import IDE.BufferMode
 import IDE.LogRef (logOutput, defaultLineLogger)
 import IDE.Pane.SourceBuffer
-    (goToSourceDefinition, maybeActiveBuf, IDEBuffer(..), replaceHLintSource)
+    (goToSourceDefinition', maybeActiveBuf, IDEBuffer(..), replaceHLintSource)
 import IDE.TextEditor (grabFocus)
 import Control.Applicative ((<$>))
 import System.FilePath ((</>), dropFileName)
@@ -57,10 +60,14 @@
 import IDE.Metainfo.Provider (getWorkspaceInfo)
 import qualified Data.Map as Map (keys, lookup)
 import Distribution.Package (PackageIdentifier(..))
+import Data.Text (Text)
+import qualified Data.Text as T
+       (replicate, unlines, init, lines, pack, unpack)
+import Data.Monoid ((<>))
 
 data HLintRecord = HLintRecord {
             condPackage :: Maybe IDEPackage
-        ,   context     :: String
+        ,   context     :: Text
         ,   condIdea    :: Maybe H.Idea
         ,   parDir      :: Maybe FilePath
         } deriving (Eq)
@@ -218,8 +225,8 @@
         Just record ->
             case record of
                 HLintRecord {condIdea = Just idea} ->
-                    goToSourceDefinition (srcSpanFilename (H.ideaSpan idea))
-                                        (Just $ Location (srcSpanStartLine (H.ideaSpan idea))
+                    goToSourceDefinition' (srcSpanFilename (H.ideaSpan idea))
+                                        (Location "" (srcSpanStartLine (H.ideaSpan idea))
                                                          (srcSpanStartColumn (H.ideaSpan idea))
                                                          (srcSpanEndLine (H.ideaSpan idea))
                                                          (srcSpanEndColumn (H.ideaSpan idea)))
@@ -255,7 +262,7 @@
                                         " location " ++ show H.parseErrorLocation) Nothing
                                     Right r -> Just r) resL
     let ideas = H.applyHints classify hint resOk
-    liftIO $ setHLint2Results store iter (packageIdentifierToString (ipdPackageId package)) ideas
+    liftIO $ setHLint2Results store iter (T.unpack $ packageIdentifierToString (ipdPackageId package)) ideas
     return ()
 
 
@@ -279,7 +286,7 @@
 
 hlint2Record dir idea = HLintRecord {
     condPackage = Nothing,
-    context     = show idea,
+    context     = T.pack $ show idea,
     condIdea    = Just idea,
     parDir      = Just dir}
 
@@ -319,10 +326,10 @@
 replaceHlint store treeView (Just sel) =
     case condIdea sel of
         Just idea | isJust (H.ideaTo idea) ->
-            let lined = lines (fromJust (H.ideaTo idea))
+            let lined = T.lines (T.pack $ fromJust (H.ideaTo idea))
                 startColumn = srcSpanStartColumn (H.ideaSpan idea)
-                source = init $ unlines (head lined :
-                                            map (\ s -> replicate startColumn ' ' ++ s) (tail lined))
+                source = T.init $ T.unlines (head lined :
+                                            map (\ s -> T.replicate startColumn " " <> s) (tail lined))
             in
                 replaceHLintSource (srcSpanFilename (H.ideaSpan idea))
                                    (srcSpanStartLine (H.ideaSpan idea))
diff --git a/src/IDE/Pane/Info.hs b/src/IDE/Pane/Info.hs
--- a/src/IDE/Pane/Info.hs
+++ b/src/IDE/Pane/Info.hs
@@ -1,5 +1,10 @@
-{-# LANGUAGE FlexibleInstances, DeriveDataTypeable, MultiParamTypeClasses,
-             CPP, ScopedTypeVariables, TypeSynonymInstances, GADTs, RecordWildCards #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE ExistentialQuantification #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -fwarn-unused-imports #-}
 -----------------------------------------------------------------------------
 --
@@ -45,6 +50,8 @@
 import System.Glib.Signals (on)
 import Control.Monad (void, when)
 import Data.Foldable (forM_)
+import qualified Data.Text as T (unpack, pack, null)
+import Data.Monoid ((<>))
 
 -- | An info pane description
 --
@@ -88,7 +95,7 @@
         createHyperLinkSupport descriptionView sw (\_ _ iter -> do
                 (beg, en) <- getIdentifierUnderCursorFromIter (iter, iter)
                 return (beg, en)) (\_ shift' slice ->
-                                    when (slice /= []) $ do
+                                    when (not $ T.null slice) $ do
                                         -- liftIO$ print ("slice",slice)
                                         triggerEventIDE (SelectInfo slice shift')
                                         return ()
@@ -140,7 +147,7 @@
         oldDescr <- liftIO $ readIORef (currentDescr info)
         liftIO $ writeIORef (currentDescr info) (Just identifierDescr)
         tb <- getBuffer v
-        setText tb (show (Present identifierDescr) ++ "\n")   -- EOL for text iters to work
+        setText tb (T.pack $ show (Present identifierDescr) ++ "\n")   -- EOL for text iters to work
         recordInfoHistory (Just identifierDescr) oldDescr
 
 setInfoStyle :: IDEAction
@@ -182,7 +189,7 @@
         Nothing -> return ()
         Just descr -> do
             prefs' <- readIDE prefs
-            openBrowser $ docuSearchURL prefs' ++ escapeURIString isAlphaNum (dscName descr)
+            openBrowser $ docuSearchURL prefs' <> T.pack (escapeURIString isAlphaNum (T.unpack $ dscName descr))
 
 populatePopupMenu :: IDERef -> IORef (Maybe Descr) -> Menu -> IO ()
 populatePopupMenu ideR currentDescr' menu = do
diff --git a/src/IDE/Pane/Log.hs b/src/IDE/Pane/Log.hs
--- a/src/IDE/Pane/Log.hs
+++ b/src/IDE/Pane/Log.hs
@@ -1,5 +1,9 @@
-{-# LANGUAGE FlexibleInstances, ScopedTypeVariables,
-   DeriveDataTypeable, MultiParamTypeClasses, TypeSynonymInstances #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 --
 -- Module      :  IDE.Pane.Log
 -- Copyright   :  (c) Juergen Nicklisch-Franken, Hamish Mackenzie
@@ -21,7 +25,7 @@
 ,   showLog
 ,   clearLog
 ,   getLog          -- ::   beta alpha
-,   appendLog       -- ::   alpha  -> String -> LogTag -> IO Int
+,   appendLog       -- ::   alpha  -> Text -> LogTag -> IO Int
 ,   markErrorInLog  -- ::   alpha  -> (Int, Int) -> IO ()
 ,   getActiveOrDefaultLogLaunch
 ,   getDefaultLogLaunch
@@ -79,8 +83,10 @@
 import IDE.Utils.GUIUtils (__)
 import Text.Printf (printf)
 import Data.Text (Text)
-import qualified Data.Text as T (length, unpack)
-import Data.Monoid ((<>))
+import qualified Data.Text as T
+       (null, all, drop, tail, init, take, reverse, isSuffixOf,
+        isPrefixOf, pack, length, unpack)
+import Data.Monoid (Monoid(..), (<>))
 import Data.List (elemIndex, isPrefixOf, isSuffixOf, findIndex)
 import Data.Foldable (forM_)
 
@@ -117,19 +123,19 @@
     return $ logLaunch $ launches Map.! defaultLogName
 
 buildLogLaunchByPackage :: IDEPackage
-                             -> IDEM (LogLaunch, String)
+                             -> IDEM (LogLaunch, Text)
 buildLogLaunchByPackage = buildLogLaunchByShownPackageId . getLogLaunchNameByPackage
 
 buildLogLaunchByPackageId :: PackageIdentifier
-                               -> IDEM (LogLaunch, String)
+                               -> IDEM (LogLaunch, Text)
 buildLogLaunchByPackageId = buildLogLaunchByShownPackageId . getLogLaunchNameByPackageId
 
-buildLogLaunchByShownPackageId :: String
-                               -> IDEM (LogLaunch, String)
+buildLogLaunchByShownPackageId :: Text
+                               -> IDEM (LogLaunch, Text)
 buildLogLaunchByShownPackageId = buildLogLaunchByName
 
-buildLogLaunchByName :: String
-                          -> IDEM (LogLaunch, String)
+buildLogLaunchByName :: Text
+                          -> IDEM (LogLaunch, Text)
 buildLogLaunchByName logName = do
         log <- getLog
         launches <- readIDE logLaunches
@@ -144,31 +150,29 @@
         incrementName name = case parseName name of
                                     Nothing -> createNewName name 0
                                     Just (number,name) -> createNewName name number
-        createNewName name number = concat [name, " (", show (number+1), ")"]
+        createNewName name number = mconcat [name, " (", T.pack (show $ number+1), ")"]
         parseName name = if surroundedByParenth (getLaunchString name) &&
-                               isNumberAndNotEmpty (init $ tail $ getLaunchString name)
+                               isNumberAndNotEmpty (T.init $ T.tail $ getLaunchString name)
                             then Just
-                                    (read $ init $ tail $ getLaunchString name,
-                                     reverse $ drop 4 $ reverse name)
+                                    (read $ T.unpack $ T.init $ T.tail $ getLaunchString name,
+                                     T.reverse $ T.drop 4 $ T.reverse name)
                             else Nothing
-        surroundedByParenth string = ("(" `isPrefixOf` string ) && (")" `isSuffixOf` string) && isNotBlank string
-        isNumberAndNotEmpty string = all isNumber string && isNotBlank string -- check if
-        getLaunchString name = reverse $ take 3 $ reverse name
-        isNotBlank [] = False
-        isNotBlank _  = True
+        surroundedByParenth string = ("(" `T.isPrefixOf` string ) && (")" `T.isSuffixOf` string) && not (T.null string)
+        isNumberAndNotEmpty string = T.all isNumber string && not (T.null string) -- check if
+        getLaunchString name = T.reverse $ T.take 3 $ T.reverse name
 
 
-getLogLaunchNameByPackage :: IDEPackage -> String
+getLogLaunchNameByPackage :: IDEPackage -> Text
 getLogLaunchNameByPackage package = getLogLaunchNameByPackageId (ipdPackageId package)
 
-getLogLaunchNameByPackageId :: PackageIdentifier -> String
-getLogLaunchNameByPackageId (PackageIdentifier pkgName pkgVersion) = show pkgName ++ show pkgVersion
+getLogLaunchNameByPackageId :: PackageIdentifier -> Text
+getLogLaunchNameByPackageId (PackageIdentifier pkgName pkgVersion) = T.pack $ show pkgName ++ show pkgVersion
 
 defaultLogName = "default"
 
 -- ^ adds arguments to ide to process them later.
 -- ^ e.g. using processhandle to kill process and name to switch between view
-addLogLaunchData :: String -> LogLaunch -> ProcessHandle -> IDEM ()
+addLogLaunchData :: Text -> LogLaunch -> ProcessHandle -> IDEM ()
 addLogLaunchData name logLaunch pid = do
     log <- getLog
     let comboBox = logLaunchBox log
@@ -214,9 +218,9 @@
 
         liftIO $ showDefaultLogLaunch comboBox
 
-showLogLaunch :: String -> IDEM ()
+showLogLaunch :: Text -> IDEM ()
 showLogLaunch name = do
-    liftIO $ putStrLn $ "showLogLaunch: name = " ++ name
+    liftIO $ putStrLn $ "showLogLaunch: name = " <> T.unpack name
     log <- getLog
     let comboBox = logLaunchBox log
 
@@ -266,23 +270,23 @@
     tags         <- textBufferGetTagTable buf
 
     errtag       <- textTagNew (Just "err")
-    set errtag[textTagForeground := "red"]
+    set errtag[textTagForeground := ("red" :: Text)]
     textTagTableAdd tags errtag
 
     frametag     <- textTagNew (Just "frame")
-    set frametag[textTagForeground := "dark green"]
+    set frametag[textTagForeground := ("dark green" :: Text)]
     textTagTableAdd tags frametag
 
     activeErrtag <- textTagNew (Just "activeErr")
-    set activeErrtag[textTagBackground := "yellow"]
+    set activeErrtag[textTagBackground := ("yellow" :: Text)]
     textTagTableAdd tags activeErrtag
 
     intputTag <- textTagNew (Just "input")
-    set intputTag[textTagForeground := "blue"]
+    set intputTag[textTagForeground := ("blue" :: Text)]
     textTagTableAdd tags intputTag
 
     infoTag <- textTagNew (Just "info")
-    set infoTag[textTagForeground := "grey"]
+    set infoTag[textTagForeground := ("grey" :: Text)]
     textTagTableAdd tags infoTag
 
     return $ LogLaunch buf
@@ -294,7 +298,7 @@
 builder' pp nb windows = do
     prefs <- readIDE prefs
     newLogLaunch <- liftIO createNewLogLaunch
-    let emptyMap = Map.empty :: Map.Map String LogLaunchData
+    let emptyMap = Map.empty :: Map.Map Text LogLaunchData
     let map = Map.insert defaultLogName (LogLaunchData newLogLaunch Nothing) emptyMap
     modifyIDE_ $ \ide -> ide { logLaunches = map}
 
@@ -320,7 +324,7 @@
             Just str ->  fontDescriptionFromString str
             Nothing  -> do
                 f    <- fontDescriptionNew
-                fontDescriptionSetFamily f "Sans"
+                fontDescriptionSetFamily f ("Sans" :: Text)
                 return f
         widgetModifyFont tv (Just fd)
         sw           <- scrolledWindowNew Nothing Nothing
@@ -467,7 +471,7 @@
     let buf = logBuffer logLaunch
     iter  <- textBufferGetEndIter buf
     textBufferSelectRange buf iter iter
-    textBufferInsert buf iter (T.unpack text)
+    textBufferInsert buf iter text
     iter2 <- textBufferGetEndIter buf
     let tagName = case tag of
                     LogTag   -> Nothing
@@ -512,7 +516,7 @@
 clearLog = do
     log <- getLog
     buf <- liftIO $ textViewGetBuffer $ logLaunchTextView log
-    liftIO $ textBufferSetText buf ""
+    liftIO $ textBufferSetText buf ("" :: Text)
 --    modifyIDE_ (\ide -> ide{allLogRefs = []})
 --    setCurrentError Nothing
 --    setCurrentBreak Nothing TODO: Check with Hamish
diff --git a/src/IDE/Pane/Modules.hs b/src/IDE/Pane/Modules.hs
--- a/src/IDE/Pane/Modules.hs
+++ b/src/IDE/Pane/Modules.hs
@@ -1,5 +1,10 @@
-{-# LANGUAGE CPP, FlexibleInstances, DeriveDataTypeable, MultiParamTypeClasses,
-             ScopedTypeVariables, TypeSynonymInstances #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Modules
@@ -48,6 +53,7 @@
 import Distribution.Text (simpleParse,display)
 import Data.Typeable (Typeable(..))
 import Control.Exception (SomeException(..),catch)
+import Control.Applicative ((<$>))
 import IDE.Package (packageConfig,addModuleToPackageDescr,delModuleFromPackageDescr,getEmptyModuleTemplate,getPackageDescriptionAndPath, ModuleLocation(..))
 import Distribution.PackageDescription
        (allBuildInfo, hsSourceDirs, hasLibs, executables, testSuites, exeName, testName,
@@ -58,7 +64,8 @@
 import Graphics.UI.Editor.Parameters
        (paraMinSize, paraMultiSel, Parameter(..), emptyParams, (<<<-),
         paraName)
-import Graphics.UI.Editor.Simple (boolEditor,staticListEditor,stringEditor)
+import Graphics.UI.Editor.Simple
+       (textEditor, boolEditor, staticListEditor)
 import Graphics.UI.Editor.Composite (maybeEditor)
 import qualified System.IO.UTF8 as UTF8  (writeFile)
 import IDE.Utils.GUIUtils (stockIdFromType, __)
@@ -68,21 +75,31 @@
 import Default (Default(..))
 import IDE.Workspaces (packageTry)
 import Control.Monad.IO.Class (MonadIO(..))
-import Control.Monad (when)
+import Control.Monad (when, void)
 import Control.Monad.Trans.Class (MonadTrans(..))
 import Control.Monad.Trans.Reader (ask)
 import IDE.Utils.GUIUtils (treeViewContextMenu)
 import System.Glib.Properties (newAttrFromMaybeStringProperty)
-import Text.Printf (printf)
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, isInfixOf, toLower, pack)
+import Data.Monoid ((<>))
+import qualified Text.Printf as S (printf)
+import Text.Printf (PrintfType)
+import qualified Data.Text.IO as T (writeFile)
 
+printf :: PrintfType r => Text -> r
+printf = S.printf . T.unpack
+
 -- | A modules pane description
 --
 
+type ModuleRecord = (Text, Maybe (ModuleDescr,PackageDescr))
+
 data IDEModules     =   IDEModules {
     outer           ::   VBox
 ,   paned           ::   HPaned
 ,   treeView        ::   TreeView
-,   treeStore       ::   TreeStore (String, Maybe (ModuleDescr,PackageDescr))
+,   treeStore       ::   TreeStore ModuleRecord
 ,   descrView       ::   TreeView
 ,   descrStore      ::   TreeStore Descr
 ,   packageScopeB   ::   RadioButton
@@ -96,7 +113,7 @@
 
 
 data ModulesState           =   ModulesState Int (Scope,Bool)
-                                    (Maybe ModuleName, Maybe String) ExpanderState
+                                    (Maybe ModuleName, Maybe Text) ExpanderState
     deriving(Eq,Ord,Read,Show,Typeable)
 
 data ExpanderState =  ExpanderState {
@@ -116,7 +133,7 @@
 
 data SelectionState = SelectionState {
     moduleS'        ::   Maybe ModuleName
-,   facetS'         ::   Maybe String
+,   facetS'         ::   Maybe Text
 ,   scope'          ::   Scope
 ,   blacklist'      ::   Bool}
  deriving (Eq,Ord,Show)
@@ -179,7 +196,7 @@
             --treeViewSetRulesHint treeView True
 
             renderer0    <- cellRendererPixbufNew
-            set renderer0 [ newAttrFromMaybeStringProperty "stock-id"  := Nothing ]
+            set renderer0 [ newAttrFromMaybeStringProperty "stock-id"  := (Nothing :: Maybe Text) ]
 
             renderer    <- cellRendererTextNew
             col         <- treeViewColumnNew
@@ -198,7 +215,7 @@
                    case snd row of
                         Nothing -> Nothing
                         Just pair -> if isJust (mdMbSourcePath (fst pair))
-                                         then Just "ide_source"
+                                         then Just ("ide_source" :: Text)
                                          else Nothing]
 
             renderer2   <- cellRendererTextNew
@@ -213,7 +230,7 @@
                 $ \row -> [
                     cellText := case snd row of
                                     Nothing -> ""
-                                    Just pair -> (display . pdPackage . snd) pair]
+                                    Just pair -> (T.pack . display . pdPackage . snd) pair]
 
             treeViewSetHeadersVisible treeView True
             treeViewSetEnableSearch treeView True
@@ -246,7 +263,7 @@
                                             else if isJust (dscMbLocation row)
                                                 then
                                                     if dscExported row
-                                                        then "ide_source"
+                                                        then ("ide_source" :: Text)
                                                         else "ide_source_local"
                                                 else "ide_empty"]
             treeViewSetHeadersVisible descrView True
@@ -366,9 +383,9 @@
                                                 else (False, False)
 
 
-selectIdentifier' :: ModuleName -> String -> IDEAction
+selectIdentifier' :: ModuleName -> Text -> IDEAction
 selectIdentifier'  moduleName symbol =
-    let nameArray = components moduleName
+    let nameArray = map T.pack $ components moduleName
     in do
         liftIO $ debugM "leksah" "selectIdentifier'"
         mods            <- getModules Nothing
@@ -392,7 +409,7 @@
                 bringPaneToFront mods
             Nothing         ->  return ()
 
-findPathFor :: String -> Maybe (Tree Descr) -> Maybe TreePath
+findPathFor :: Text -> Maybe (Tree Descr) -> Maybe TreePath
 findPathFor symbol (Just (Node _ forest)) =
     foldr ( \i mbTreePath -> findPathFor' [i] (forest !! i) mbTreePath)
                             Nothing  [0 .. ((length forest) - 1)]
@@ -407,7 +424,7 @@
                             Nothing     [0 .. ((length sub) - 1)]
 findPathFor symbol Nothing = Nothing
 
-treePathFromNameArray :: Maybe ModTree -> [String] -> [Int] -> Maybe [Int]
+treePathFromNameArray :: Maybe ModTree -> [Text] -> [Int] -> Maybe [Int]
 treePathFromNameArray (Just tree) [] accu      =   Just (reverse accu)
 treePathFromNameArray (Just tree) (h:t) accu   =
     let names   =   map (\t -> fst $ rootLabel t) (subForest tree)
@@ -418,8 +435,8 @@
 treePathFromNameArray Nothing _ _  = Nothing
 
 treeViewSearch :: TreeView
-    -> TreeStore (String, Maybe (ModuleDescr,PackageDescr))
-    -> String
+    -> TreeStore ModuleRecord
+    -> Text
     -> TreeIter
     -> IO Bool
 treeViewSearch treeView treeStore string iter =  do
@@ -436,23 +453,23 @@
     let str2      =  case snd val of
                         Just (mod,_) ->  showPackModule  (mdModuleId mod)
                         Nothing -> ""
-    let res       =  isInfixOf (map toLower string) (map toLower str2)
+    let res       =  T.isInfixOf (T.toLower string) (T.toLower str2)
     return res
 
-searchInModSubnodes :: ModTree -> String -> Bool
+searchInModSubnodes :: ModTree -> Text -> Bool
 searchInModSubnodes tree str =
     not $ null
         $ filter (\ (_,mbPair) ->
             case mbPair of
                 Nothing -> False
                 Just (mod,_) ->
-                    let cstr = show (Present (mdModuleId mod))
-                    in  isInfixOf (map toLower str) (map toLower cstr))
+                    let cstr = T.pack $ show (Present (mdModuleId mod))
+                    in  T.isInfixOf (T.toLower str) (T.toLower cstr))
                             $ concatMap flatten (subForest tree)
 
 descrViewSearch :: TreeView
     -> TreeStore Descr
-    -> String
+    -> Text
     -> TreeIter
     -> IO Bool
 descrViewSearch descrView descrStore string iter = do
@@ -466,17 +483,17 @@
         in when found $ do
             treeViewExpandRow descrView path False
             return ()
-    return (isInfixOf (map toLower string) (map toLower (descrTreeText val)))
+    return (T.isInfixOf (T.toLower string) (T.toLower (descrTreeText val)))
 
-searchInFacetSubnodes :: DescrTree -> String -> Bool
+searchInFacetSubnodes :: DescrTree -> Text -> Bool
 searchInFacetSubnodes tree str =
     not $ null
         $ filter (\ val ->
-            isInfixOf (map toLower str) (map toLower (descrTreeText val)))
+            T.isInfixOf (T.toLower str) (T.toLower (descrTreeText val)))
                 $ concatMap flatten (subForest tree)
 
 fillFacets :: TreeView
-    -> TreeStore (String, Maybe (ModuleDescr,PackageDescr))
+    -> TreeStore ModuleRecord
     -> TreeView
     -> TreeStore Descr
     -> IO ()
@@ -498,8 +515,8 @@
             ->  treeStoreClear descrStore
 
 getSelectionTree ::  TreeView
-    ->  TreeStore (String, Maybe (ModuleDescr,PackageDescr))
-    -> IO (Maybe (String, Maybe (ModuleDescr,PackageDescr)))
+    ->  TreeStore ModuleRecord
+    -> IO (Maybe ModuleRecord)
 getSelectionTree treeView treeStore = do
     liftIO $ debugM "leksah" "getSelectionTree"
     treeSelection   <-  treeViewGetSelection treeView
@@ -540,7 +557,7 @@
             return ()
         _       ->  return ()
 
-findDescription :: SymbolTable alpha => PackModule -> alpha -> String -> Maybe (String,Descr)
+findDescription :: SymbolTable alpha => PackModule -> alpha -> Text -> Maybe (Text,Descr)
 findDescription md st s     =
     case filter (\id -> case dsMbModu id of
                             Nothing -> False
@@ -548,7 +565,7 @@
         [] -> Nothing
         l  -> Just (s,head l)
 
-getEmptyDefaultScope :: Map String [Descr]
+getEmptyDefaultScope :: Map Text [Descr]
 getEmptyDefaultScope = Map.empty
 
 fillModulesList :: (Scope,Bool) -> IDEAction
@@ -625,12 +642,12 @@
 type DescrTree = Tree Descr
 
 
-descrTreeText :: Descr -> String
-descrTreeText (Real (RealDescr id _ _ _ _ (InstanceDescr binds) _)) = id ++ " " ++ printBinds binds
+descrTreeText :: Descr -> Text
+descrTreeText (Real (RealDescr id _ _ _ _ (InstanceDescr binds) _)) = id <> " " <> printBinds binds
     where
         printBinds []       =   ""
         printBinds (a:[])   =   a
-        printBinds (a:b)    =   a ++ " " ++ printBinds b
+        printBinds (a:b)    =   a <> " " <> printBinds b
 descrTreeText d = dscName d
 
 descrIdType :: Descr -> DescrType
@@ -717,10 +734,10 @@
     matches _ node (forest,b)  = (node:forest,b)
 
 
-defaultRoot :: Tree (String, Maybe (ModuleDescr,PackageDescr))
+defaultRoot :: Tree ModuleRecord
 defaultRoot = Node ("",Just (getDefault,getDefault)) []
 
-type ModTree = Tree (String, Maybe (ModuleDescr,PackageDescr))
+type ModTree = Tree ModuleRecord
 --
 -- | Make a Tree with a module desription, package description pairs tree to display.
 --   Their are nodes with a label but without a module (like e.g. Data).
@@ -734,13 +751,13 @@
 
 insertPairsInTree :: ModTree -> (ModuleDescr,PackageDescr) -> ModTree
 insertPairsInTree tree pair =
-    let nameArray           =   components $ modu $ mdModuleId $ fst pair
+    let nameArray           =   map T.pack . components . modu . mdModuleId $ fst pair
         (startArray,last)   =   splitAt (length nameArray - 1) nameArray
         pairedWith          =   (map (\n -> (n,Nothing)) startArray) ++ [(head last,Just pair)]
     in  insertNodesInTree pairedWith tree
 
 
-insertNodesInTree :: [(String, Maybe (ModuleDescr,PackageDescr))] -> ModTree -> ModTree
+insertNodesInTree :: [ModuleRecord] -> ModTree -> ModTree
 insertNodesInTree  [p1@(str1,Just pair)] (Node p2@(str2,mbPair) forest2) =
     case partition (\ (Node (s,_) _) -> s == str1) forest2 of
         ([found],rest) -> case found of
@@ -762,10 +779,10 @@
         (found,rest)   -> Node p  (insertNodesInTree tl (head found) : tail found ++ rest)
 
 insertNodesInTree [] n = n
-insertNodesInTree _ _      =   error (__ "Modules>>insertNodesInTree: Should not happen2")
+insertNodesInTree _ _      =   error (T.unpack $ __ "Modules>>insertNodesInTree: Should not happen2")
 
 
-makeNodes :: [(String,Maybe (ModuleDescr,PackageDescr))] -> ModTree
+makeNodes :: [(Text,Maybe (ModuleDescr,PackageDescr))] -> ModTree
 makeNodes [(str,mbPair)]    =   Node (str,mbPair) []
 makeNodes ((str,mbPair):tl) =   Node (str,mbPair) [makeNodes tl]
 makeNodes _                 =   throwIDE (__ "Impossible in makeNodes")
@@ -776,8 +793,17 @@
 sortTree :: Ord a => Tree a -> Tree a
 sortTree (Node l forest)    =   Node l (sort (map sortTree forest))
 
+getSelectedModuleFile :: Maybe ModuleRecord -> Maybe FilePath
+getSelectedModuleFile sel =
+    case sel of
+        Just (_,Just (m,p)) -> case (mdMbSourcePath m, pdMbSourcePath p) of
+                                (Just fp, Just pp) -> Just $ dropFileName pp </> fp
+                                (Just fp, Nothing) -> Just fp
+                                _     ->  Nothing
+        otherwise       ->  Nothing
+
 modulesContextMenu :: IDERef
-                   -> TreeStore (String, Maybe (ModuleDescr,PackageDescr))
+                   -> TreeStore ModuleRecord
                    -> TreeView
                    -> Menu
                    -> IO ()
@@ -785,14 +811,10 @@
     liftIO $ debugM "leksah" "modulesContextMenu"
     item1           <-  menuItemNewWithLabel (__ "Edit source")
     item1 `on` menuItemActivate $ do
-        sel         <-  getSelectionTree treeView store
-        case sel of
-            Just (_,Just (m,_)) -> case mdMbSourcePath m of
-                                    Nothing     ->  return ()
-                                    Just fp     ->  do
-                                        reflectIDE (selectSourceBuf fp) ideR
-                                        return ()
-            otherwise       ->  return ()
+        mbFile <- getSelectedModuleFile <$> getSelectionTree treeView store
+        case mbFile of
+            Nothing -> return ()
+            Just fp -> void $ reflectIDE (selectSourceBuf fp) ideR
     sep1 <- separatorMenuItemNew
     item2           <-  menuItemNewWithLabel (__ "Expand here")
     item2 `on` menuItemActivate $ expandHere treeView
@@ -807,24 +829,22 @@
     item6 `on` menuItemActivate $ reflectIDE (packageTry $ addModule' treeView store) ideR
     item7           <-  menuItemNewWithLabel (__ "Delete module")
     item7 `on` menuItemActivate $ do
-        sel         <-  getSelectionTree treeView store
-        case sel of
-            Just (_,Just (m,_)) -> case mdMbSourcePath m of
-                                    Nothing     ->  return ()
-                                    Just fp     ->  do
-                                        resp <- reflectIDE (respDelModDialog)ideR
-                                        if (resp == False) then return ()
-                                            else do
-                                                exists <- doesFileExist fp
-                                                if exists
-                                                   then do
-                                                     reflectIDE (liftIO $ removeFile fp) ideR
-                                                     reflectIDE (packageTry $ delModule treeView store)ideR
-                                                   else do
-                                                     reflectIDE (packageTry $ delModule treeView store)ideR
-                                                reflectIDE (packageTry packageConfig) ideR
-                                                return ()
-            otherwise       ->  return ()
+        mbFile <- getSelectedModuleFile <$> getSelectionTree treeView store
+        case mbFile of
+            Nothing     ->  return ()
+            Just fp     ->  do
+                resp <- reflectIDE (respDelModDialog)ideR
+                if (resp == False) then return ()
+                    else do
+                        exists <- doesFileExist fp
+                        if exists
+                           then do
+                             reflectIDE (liftIO $ removeFile fp) ideR
+                             reflectIDE (packageTry $ delModule treeView store)ideR
+                           else do
+                             reflectIDE (packageTry $ delModule treeView store)ideR
+                        reflectIDE (packageTry packageConfig) ideR
+                        return ()
     sel         <-  getSelectionTree treeView store
     case sel of
         Just (s, Nothing) -> do
@@ -838,7 +858,7 @@
         otherwise -> return ()
 
 modulesSelect :: IDERef
-              -> TreeStore (String, Maybe (ModuleDescr,PackageDescr))
+              -> TreeStore ModuleRecord
               -> TreeView
               -> TreePath
               -> TreeViewColumn
@@ -846,13 +866,10 @@
 modulesSelect ideR store treeView path _ = do
     liftIO $ debugM "leksah" "modulesSelect"
     treeViewExpandRow treeView path False
-    sel <- treeStoreGetValue store path
-    case sel of
-        (_,Just (m,_)) -> do
-            case mdMbSourcePath m of
-                Nothing -> return ()
-                Just fp -> liftIO $ reflectIDE (selectSourceBuf fp) ideR >> return ()
-        _ -> return ()
+    mbFile <- getSelectedModuleFile <$> getSelectionTree treeView store
+    case mbFile of
+        Nothing -> return ()
+        Just fp -> liftIO $ reflectIDE (selectSourceBuf fp) ideR >> return ()
 
 descrViewContextMenu :: IDERef
                    -> TreeStore Descr
@@ -959,7 +976,7 @@
     applyExpanderState
     liftIO $ bringPaneToFront mods
 
-selectNames :: (Maybe ModuleName, Maybe String) -> IDEAction
+selectNames :: (Maybe ModuleName, Maybe Text) -> IDEAction
 selectNames (mbModuleName, mbIdName) = do
     liftIO $ debugM "leksah" "selectIdentifier"
     mods <- getModules Nothing
@@ -970,7 +987,7 @@
             selF        <-  treeViewGetSelection (descrView mods)
             treeSelectionUnselectAll  selF
         Just moduleName ->
-            let nameArray = components moduleName
+            let nameArray = map T.pack $ components moduleName
             in do
                 mbTree              <-  liftIO $ treeStoreGetTreeSave (treeStore mods) []
                 case treePathFromNameArray mbTree nameArray [] of
@@ -999,7 +1016,7 @@
 
 reloadKeepSelection :: Bool -> IDEAction
 reloadKeepSelection isInitial = do
-    liftIO $ debugM "leksah" ((__ ">>>Info Changed!!! ") ++ show isInitial)
+    liftIO . debugM "leksah" $ (T.unpack $ __ ">>>Info Changed!!! ") ++ show isInitial
     mbMod <- getPane
     case mbMod of
         Nothing -> return ()
@@ -1055,7 +1072,7 @@
         []     -> return ()
         (hd:_) -> treeViewCollapseRow treeView hd >> return ()
 
-delModule :: TreeView -> TreeStore (String, Maybe (ModuleDescr,PackageDescr)) -> PackageAction
+delModule :: TreeView -> TreeStore ModuleRecord -> PackageAction
 delModule treeview store = do
     liftIO $ debugM "leksah" "delModule"
     window <- liftIDE $ getMainWindow
@@ -1066,14 +1083,14 @@
         (treePath:_) -> liftIO $ mapM (treeStoreGetValue store)
                                     $ map (\n -> take n treePath)  [1 .. length treePath]
 
-    liftIDE $ ideMessage Normal (printf (__ "categories: %s") (show categories))
+    liftIDE $ ideMessage Normal (T.pack $ printf (__ "categories: %s") (show categories))
 
     let modPacDescr = snd(last categories)
     case modPacDescr of
         Nothing     ->   liftIDE $ ideMessage Normal (__ "This should never be shown!")
         Just(md,_)  -> do
                          let modName = modu.mdModuleId $ md
-                         liftIDE $ ideMessage Normal ("modName: " ++ (show modName))
+                         liftIDE $ ideMessage Normal ("modName: " <> T.pack (show modName))
                          delModuleFromPackageDescr modName
 
 respDelModDialog :: IDEM (Bool)
@@ -1090,7 +1107,7 @@
         return resp
     return $ resp == ResponseUser 1
 
-addModule' :: TreeView -> TreeStore (String, Maybe (ModuleDescr,PackageDescr)) -> PackageAction
+addModule' :: TreeView -> TreeStore ModuleRecord -> PackageAction
 addModule' treeView store = do
     liftIO $ debugM "leksah" "addModule'"
     sel   <- liftIO $ treeViewGetSelection treeView
@@ -1101,6 +1118,7 @@
                                     $ map (\n -> take n treePath)  [1 .. length treePath]
     addModule categories
 
+addModule :: [ModuleRecord] -> PackageAction
 addModule categories = do
     liftIO $ debugM "leksah" "selectIdentifier"
     mbPD <- liftIDE $ getPackageDescriptionAndPath
@@ -1108,29 +1126,31 @@
         Nothing             -> liftIDE $ ideMessage Normal (__ "No package description")
         Just (pd,cabalPath) -> let srcPaths = nub $ concatMap hsSourceDirs $ allBuildInfo pd
                                    rootPath = dropFileName cabalPath
-                                   modPath  = foldr (\a b -> a ++ "." ++ b) ""
+                                   modPath  = foldr (\a b -> a <> "." <> b) ""
                                                 (map fst categories)
                                in do
             window' <- liftIDE getMainWindow
             mbResp <- liftIO $ addModuleDialog window' modPath srcPaths (hasLibs pd) $
-                   map exeName (executables pd) ++ map testName (testSuites pd) ++ map benchmarkName (benchmarks pd)
+                      map (T.pack . exeName)  (executables pd)
+                   ++ map (T.pack . testName) (testSuites pd)
+                   ++ map (T.pack . benchmarkName) (benchmarks pd)
             case mbResp of
                 Nothing                -> return ()
                 Just addMod@(AddModule modPath srcPath libExposed exesAndTests) ->
-                    case simpleParse modPath of
-                        Nothing         -> liftIDE $ ideMessage Normal (printf (__ "Not a valid module name : %s") modPath)
+                    case simpleParse $ T.unpack modPath of
+                        Nothing         -> liftIDE $ ideMessage Normal (T.pack $ printf (__ "Not a valid module name : %s") (T.unpack modPath))
                         Just moduleName -> do
                             let  target = srcPath </> toFilePath moduleName ++ ".hs"
                             liftIO $ createDirectoryIfMissing True (dropFileName target)
                             alreadyExists <- liftIO $ doesFileExist target
                             if alreadyExists
                                 then do
-                                    liftIDE $ ideMessage Normal (printf (__ "File already exists! Importing existing file %s.hs") (takeBaseName target))
+                                    liftIDE $ ideMessage Normal (T.pack $ printf (__ "File already exists! Importing existing file %s.hs") (takeBaseName target))
                                     addModuleToPackageDescr moduleName $ addModuleLocations addMod
                                     packageConfig
                                 else do
                                     template <- liftIO $ getEmptyModuleTemplate pd modPath
-                                    liftIO $ UTF8.writeFile target template
+                                    liftIO $ T.writeFile target template
                                     addModuleToPackageDescr moduleName $ addModuleLocations addMod
                                     packageConfig
                                     liftIDE $ fileOpenThis target
@@ -1139,10 +1159,10 @@
 --  Yet another stupid little dialog
 
 data AddModule = AddModule {
-    moduleName   :: String,
+    moduleName   :: Text,
     sourceRoot   :: FilePath,
     libExposed   :: Maybe Bool,
-    exesAndTests :: Set String}
+    exesAndTests :: Set Text}
 
 addModuleLocations :: AddModule -> [ModuleLocation]
 addModuleLocations addMod = lib (libExposed addMod)
@@ -1152,7 +1172,7 @@
     lib (Just False) = [LibOtherMod]
     lib Nothing = []
 
-addModuleDialog :: Window -> String -> [String] -> Bool -> [String] -> IO (Maybe AddModule)
+addModuleDialog :: Window -> Text -> [FilePath] -> Bool -> [Text] -> IO (Maybe AddModule)
 addModuleDialog parent modString sourceRoots hasLib exesTests = do
     liftIO $ debugM "leksah" "addModuleDialog"
     dia                        <-   dialogNew
@@ -1188,22 +1208,22 @@
         ResponseOk    -> return value
         _             -> return Nothing
 
-moduleFields :: [FilePath] -> Bool -> [String] -> FieldDescription AddModule
+moduleFields :: [FilePath] -> Bool -> [Text] -> FieldDescription AddModule
 moduleFields list hasLibs exesTests = VFD emptyParams $ [
         mkField
             (paraName <<<- ParaName ((__ "New module "))
                     $ emptyParams)
             moduleName
             (\ a b -> b{moduleName = a})
-            (stringEditor (const True) True),
+            (textEditor (const True) True),
         mkField
             (paraName <<<- ParaName ((__ "Root of the source path"))
                 $ paraMultiSel <<<- ParaMultiSel False
                     $ paraMinSize <<<- ParaMinSize (-1, 120)
                         $ emptyParams)
-            (\a -> sourceRoot a)
-            (\ a b -> b{sourceRoot = a})
-            (staticListEditor list id)]
+            (\a -> T.pack $ sourceRoot a)
+            (\ a b -> b{sourceRoot = T.unpack a})
+            (staticListEditor (map T.pack list) id)]
         ++ (if hasLibs
                 then [
                     mkField
@@ -1215,7 +1235,7 @@
                 else [])
         ++ map (\ name ->
             mkField
-                (paraName <<<- ParaName ((__ "Include in ") ++ name)
+                (paraName <<<- ParaName ((__ "Include in ") <> name)
                         $ emptyParams)
                 (Set.member name . exesAndTests)
                 (\ a b -> b{exesAndTests = (if a then Set.insert else Set.delete) name (exesAndTests b)})
@@ -1319,7 +1339,7 @@
     liftIO $ writeIORef (oldSelection mods) (oldSel{moduleS'= selMod, facetS' = selFacet})
     return ()
 
-replaySelHistory :: Maybe ModuleName -> Maybe String -> IDEAction
+replaySelHistory :: Maybe ModuleName -> Maybe Text -> IDEAction
 replaySelHistory mbModName mbFacetName = do
     liftIO $ debugM "leksah" "replaySelHistory"
     mods <- getModules Nothing
diff --git a/src/IDE/Pane/PackageEditor.hs b/src/IDE/Pane/PackageEditor.hs
--- a/src/IDE/Pane/PackageEditor.hs
+++ b/src/IDE/Pane/PackageEditor.hs
@@ -1,6 +1,11 @@
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE FlexibleInstances, ScopedTypeVariables, DeriveDataTypeable,
-             CPP, MultiParamTypeClasses, TypeSynonymInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.PackageEditor
@@ -44,19 +49,11 @@
 import Distribution.ModuleName(ModuleName)
 import Data.Typeable (Typeable(..))
 import Graphics.UI.Editor.Composite
-    (versionEditor,
-     versionRangeEditor,
-     dependenciesEditor,
-     stringsEditor,
-     filesEditor,
-     tupel3Editor,
-     eitherOrEditor,
-     maybeEditor,
-     pairEditor,
-     ColumnDescr(..),
-     multisetEditor)
+       (versionEditor, versionRangeEditor,
+        dependenciesEditor, textsEditor, filesEditor, tupel3Editor,
+        eitherOrEditor, maybeEditor, pairEditor, ColumnDescr(..),
+        multisetEditor)
 import Distribution.Text (simpleParse, display)
-import MyMissing
 import Graphics.UI.Editor.Parameters
     (paraInnerPadding,
      paraInnerAlignment,
@@ -74,16 +71,14 @@
      paraName,
      getParameterPrim)
 import Graphics.UI.Editor.Simple
-       (comboEntryEditor, staticListMultiEditor, intEditor, boolEditor,
-        fileEditor, comboSelectionEditor, multilineStringEditor,
-        stringEditor)
+       (stringEditor, comboEntryEditor,
+        staticListMultiEditor, intEditor, boolEditor, fileEditor,
+        comboSelectionEditor, multilineStringEditor, textEditor)
 import Graphics.UI.Editor.Basics
        (Notifier, Editor(..), GUIEventSelector(..), GUIEvent(..))
 import Distribution.Compiler
     (CompilerFlavor(..))
-#if !MIN_VERSION_Cabal(1,11,0)
 import Distribution.Simple (knownExtensions)
-#endif
 import Distribution.Simple (Extension(..), VersionRange, anyVersion)
 import Default (Default(..))
 import IDE.Utils.GUIUtils
@@ -92,6 +87,7 @@
 
 import qualified Graphics.UI.Gtk.Gdk.Events as GTK (Event(..))
 import Data.List (isPrefixOf, sort, nub)
+import Data.Text (Text)
 import Control.Monad.Trans.Reader (ask)
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad.Trans.Class (lift)
@@ -100,17 +96,26 @@
        (writeGenericPackageDescription)
 import Distribution.Version (Version(..), orLaterVersion)
 
-import Text.Printf (printf)
 import Control.Applicative ((<*>), (<$>))
-import qualified Data.Conduit.Util as CU (zipSinks)
 import IDE.Utils.Tool (ToolOutput(..))
 import System.Exit (ExitCode(..))
 import qualified Data.Conduit.List as CL (fold)
-import qualified Data.Conduit as C (Sink)
+import qualified Data.Conduit as C (Sink, ZipSink(..), getZipSink)
 import IDE.Utils.ExternalTool (runExternalTool')
 import qualified System.IO.Strict as S (readFile)
 import Data.Char (toLower)
+import qualified Data.Text as T
+       (replace, span, splitAt, isPrefixOf, length, toLower, lines,
+        unlines, pack, unpack, null)
+import Data.Monoid ((<>))
+import qualified Data.Text.IO as T (writeFile, readFile)
+import qualified Text.Printf as S (printf)
+import Text.Printf (PrintfType)
+import MyMissing (forceJust)
 
+printf :: PrintfType r => Text -> r
+printf = S.printf . T.unpack
+
 -- | Get the last item
 sinkLast = CL.fold (\_ a -> Just a) Nothing
 
@@ -227,9 +232,9 @@
     unknown _ = True
 
 data NewPackage = NewPackage {
-    newPackageName :: String,
+    newPackageName :: Text,
     newPackageParentDir :: FilePath,
-    templatePackage :: String}
+    templatePackage :: Text}
 
 packageFields :: FilePath -> FieldDescription NewPackage
 packageFields workspaceDir = VFD emptyParams [
@@ -238,7 +243,7 @@
                     $ emptyParams)
             newPackageName
             (\ a b -> b{newPackageName = a})
-            (stringEditor (const True) True),
+            (textEditor (const True) True),
         mkField
             (paraName <<<- ParaName ((__ "Parent directory"))
                 $ paraMinSize <<<- ParaMinSize (-1, 120)
@@ -271,8 +276,8 @@
     lower                      <-   dialogGetActionArea dia
     (widget,inj,ext,_)         <-   buildEditor (packageFields workspaceDir)
                                         (NewPackage "" workspaceDir "hello")
-    okButton <- dialogAddButton dia "Ok" ResponseOk
-    dialogAddButton dia "Cancel" ResponseCancel
+    okButton <- dialogAddButton dia (__"Create Package") ResponseOk
+    dialogAddButton dia (__"Cancel") ResponseCancel
     boxPackStart (castToBox upper) widget PackGrow 7
     set okButton [widgetCanDefault := True]
     widgetGrabDefault okButton
@@ -291,17 +296,17 @@
     mbNewPackage <- liftIO $ newPackageDialog (head windows) workspaceDir
     case mbNewPackage of
         Nothing -> return ()
-        Just NewPackage{..} | null templatePackage -> do
-            let dirName = newPackageParentDir </> newPackageName
+        Just NewPackage{..} | T.null templatePackage -> do
+            let dirName = newPackageParentDir </> T.unpack newPackageName
             mbCabalFile <-  liftIO $ cabalFileName dirName
             window <- getMainWindow
             case mbCabalFile of
                 Just cfn -> do
                     add <- liftIO $ do
                         md <- messageDialogNew (Just window) [] MessageQuestion ButtonsCancel
-                            $ (printf (__
+                             (T.pack $ printf (__
                               "There is already file %s in this directory. Would you like to add this package to the workspace?")
-                              (takeFileName cfn) )
+                              (takeFileName cfn))
                         dialogAddButton md (__ "_Add Package") (ResponseUser 1)
                         dialogSetDefaultResponse md (ResponseUser 1)
                         set md [ windowWindowPosition := WinPosCenterOnParent ]
@@ -316,8 +321,8 @@
                         then return True
                         else liftIO $ do
                             md <- messageDialogNew (Just window) [] MessageQuestion ButtonsCancel
-                                $ (printf (__
-                                   "The path you have choosen %s is not an empty directory. Are you sure you want to make a new package here?")
+                                 (T.pack $ printf (__
+                                  "The path you have choosen %s is not an empty directory. Are you sure you want to make a new package here?")
                                   dirName)
                             dialogAddButton md (__ "_Make Package Here") (ResponseUser 1)
                             dialogSetDefaultResponse md (ResponseUser 1)
@@ -329,7 +334,7 @@
                         modules <- liftIO $ allModules dirName
                         let Just initialVersion = simpleParse "0.0.1"
                         editPackage emptyPackageDescription {
-                            package   = PackageIdentifier (PackageName newPackageName)
+                            package   = PackageIdentifier (PackageName $ T.unpack newPackageName)
                                                           initialVersion
                           , buildType = Just Simple
                           , specVersionRaw = Right (orLaterVersion (Version [1,2] []))
@@ -337,12 +342,12 @@
                                 Dependency (PackageName "base") anyVersion
                               , Dependency (PackageName "QuickCheck") anyVersion]
                           , executables = [emptyExecutable {
-                                exeName    = newPackageName
+                                exeName    = T.unpack newPackageName
                               , modulePath = "Main.hs"
                               , buildInfo  = emptyBuildInfo {
                                     hsSourceDirs = ["src"]}}]
                           , testSuites = [emptyTestSuite {
-                                    testName = "test-" ++ newPackageName
+                                    testName = "test-" ++ T.unpack newPackageName
                                   , testInterface = (TestSuiteExeV10 (Version [1,0] []) "Main.hs")
                                   , testBuildInfo = emptyBuildInfo {
                                         hsSourceDirs = ["src"]
@@ -352,14 +357,15 @@
                     return ()
         Just NewPackage{..} -> cabalUnpack newPackageParentDir templatePackage False (Just newPackageName) log (activateAction False)
 
+standardSetup :: Text
 standardSetup = "#!/usr/bin/runhaskell \n"
-                    ++ "> module Main where\n"
-                    ++ "> import Distribution.Simple\n"
-                    ++ "> main :: IO ()\n"
-                    ++ "> main = defaultMain\n\n"
+                    <> "> module Main where\n"
+                    <> "> import Distribution.Simple\n"
+                    <> "> main :: IO ()\n"
+                    <> "> main = defaultMain\n\n"
 
 data ClonePackageSourceRepo = ClonePackageSourceRepo {
-    packageToClone :: String,
+    packageToClone :: Text,
     cloneParentDir :: FilePath}
 
 cloneFields :: [PackageId] -> FilePath -> FieldDescription ClonePackageSourceRepo
@@ -369,7 +375,7 @@
                     $ emptyParams)
             packageToClone
             (\ a b -> b{packageToClone = a})
-            (comboEntryEditor ((sort . nub) (map (display . pkgName) packages))),
+            (comboEntryEditor ((sort . nub) (map (T.pack . display . pkgName) packages))),
         mkField
             (paraName <<<- ParaName ((__ "Parent directory"))
                 $ paraMinSize <<<- ParaMinSize (-1, 120)
@@ -392,8 +398,8 @@
     lower                      <-   dialogGetActionArea dia
     (widget,inj,ext,_)         <-   buildEditor (cloneFields packages workspaceDir)
                                         (ClonePackageSourceRepo "" workspaceDir)
-    okButton <- dialogAddButton dia "Ok" ResponseOk
-    dialogAddButton dia "Cancel" ResponseCancel
+    okButton <- dialogAddButton dia (__"Clone Package") ResponseOk
+    dialogAddButton dia (__"Cancel") ResponseCancel
     boxPackStart (castToBox upper) widget PackGrow 7
     set okButton [widgetCanDefault := True]
     widgetGrabDefault okButton
@@ -414,67 +420,68 @@
         Nothing -> return ()
         Just ClonePackageSourceRepo{..} -> cabalUnpack cloneParentDir packageToClone True Nothing log activateAction
 
-cabalUnpack :: FilePath -> String -> Bool -> Maybe String -> C.Sink ToolOutput IDEM () -> (FilePath -> IDEAction) -> IDEAction
+cabalUnpack :: FilePath -> Text -> Bool -> Maybe Text -> C.Sink ToolOutput IDEM () -> (FilePath -> IDEAction) -> IDEAction
 cabalUnpack parentDir packageToUnpack sourceRepo mbNewName log activateAction = do
-    let tempDir = parentDir </> (packageToUnpack ++ ".leksah.temp")
+    let tempDir = parentDir </> (T.unpack packageToUnpack ++ ".leksah.temp")
     liftIO $ do
         oldDirExists <- doesDirectoryExist tempDir
         when oldDirExists $ removeDirectoryRecursive tempDir
         createDirectory tempDir
     runExternalTool' (__ "Unpacking") "cabal" (["unpack"]
               ++ (if sourceRepo then ["--source-repository"] else [])
-              ++ ["--destdir=" ++ tempDir, packageToUnpack]) tempDir $ do
-        (mbLastOutput, _) <- CU.zipSinks sinkLast log
+              ++ ["--destdir=" <> T.pack tempDir, packageToUnpack]) tempDir $ do
+        mbLastOutput <- C.getZipSink $ const <$> C.ZipSink sinkLast <*> C.ZipSink log
         case mbLastOutput of
             Just (ToolExit ExitSuccess) -> do
                 contents <- liftIO $ getDirectoryContents tempDir
                 case filter (not . isPrefixOf ".") contents of
                     [] -> do
                         liftIO $ removeDirectoryRecursive tempDir
-                        lift $ ideMessage High $ "Nothing found in " ++ tempDir ++ " after doing a cabal unpack."
+                        lift $ ideMessage High $ "Nothing found in " <> T.pack tempDir <> " after doing a cabal unpack."
                     [repoName] -> do
-                        let destDir = parentDir </> (fromMaybe repoName mbNewName)
+                        let destDir = parentDir </> (fromMaybe repoName $ T.unpack <$> mbNewName)
                         exists <- liftIO $ (||) <$> doesDirectoryExist destDir <*> doesFileExist destDir
                         if exists
-                            then lift $ ideMessage High $ destDir ++ " already exists"
+                            then lift $ ideMessage High $ T.pack destDir <> " already exists"
                             else do
                                 liftIO $ renameDirectory (tempDir </> repoName) destDir
                                 mbCabalFile <- liftIO $ cabalFileName destDir
                                 window <- lift $ getMainWindow
                                 lift $ case (mbCabalFile, mbNewName) of
                                     (Just cfn, Just newName) -> do
-                                        let newCfn = takeDirectory cfn </> newName ++ ".cabal"
+                                        let newCfn = takeDirectory cfn </> (T.unpack newName) ++ ".cabal"
                                         when (cfn /= newCfn) . liftIO $ do
-                                            s <- S.readFile cfn
-                                            writeFile newCfn $ renameCabalFile (takeBaseName cfn) newName s
+                                            s <- T.readFile cfn
+                                            T.writeFile newCfn $ renameCabalFile (T.pack $ takeBaseName cfn) newName s
                                             removeFile cfn
                                         activateAction newCfn
                                     (Just cfn, _) -> activateAction cfn
-                                    _  -> ideMessage High $ "Unpacked source reposity to " ++ destDir ++ " but it does not contain a .cabal file in the root directory."
+                                    _  -> ideMessage High $ "Unpacked source reposity to " <> T.pack destDir <> " but it does not contain a .cabal file in the root directory."
                         liftIO $ removeDirectoryRecursive tempDir
                     _ -> do
                         liftIO $ removeDirectoryRecursive tempDir
-                        lift $ ideMessage High $ "More than one subdirectory found in " ++ tempDir ++ " after doing a cabal unpack."
+                        lift $ ideMessage High $ "More than one subdirectory found in " <> T.pack tempDir <> " after doing a cabal unpack."
 
             _ -> do
                 liftIO $ removeDirectoryRecursive tempDir
-                lift $ ideMessage High $ "Failed to unpack source reposity to " ++ tempDir
+                lift $ ideMessage High $ "Failed to unpack source reposity to " <> T.pack tempDir
 
-renameCabalFile :: String -> String -> String -> String
-renameCabalFile oldName newName = unlines . map renameLine . lines
+renameCabalFile :: Text -> Text -> Text -> Text
+renameCabalFile oldName newName = T.unlines . map renameLine . T.lines
     where
         prefixes = ["name:", "executable ", "test-suite "]
-        prefixesWithLength = zip prefixes $ map length prefixes
-        renameLine :: String -> String
+        prefixesWithLength :: [(Text, Int)]
+        prefixesWithLength = zip prefixes $ map T.length prefixes
+        renameLine :: Text -> Text
         renameLine line =
-            case catMaybes $ map (rename (line, map toLower line)) prefixesWithLength of
+            case catMaybes $ map (rename (line, T.toLower line)) prefixesWithLength of
                 l:_ -> l
                 []  -> line
-        rename :: (String, String) -> (String, Int) -> Maybe String
-        rename (line, lcLine) (lcPrefix, pLen) | lcPrefix `isPrefixOf` lcLine =
-            let (prefix, rest) = splitAt pLen line
-                (spaces, value) = span (==' ') rest in
-            Just $ prefix ++ spaces ++ replace oldName newName value
+        rename :: (Text, Text) -> (Text, Int) -> Maybe Text
+        rename (line, lcLine) (lcPrefix, pLen) | lcPrefix `T.isPrefixOf` lcLine =
+            let (prefix, rest) = T.splitAt pLen line
+                (spaces, value) = T.span (==' ') rest in
+            Just $ prefix <> spaces <> T.replace oldName newName value
         rename _ _ = Nothing
 
 --  ---------------------------------------------------------------------
@@ -504,14 +511,14 @@
         benchmarks'
         mbLib' buildInfos) =
     let     exes = map (\ (Executable' s fb bii) -> if bii + 1 > length buildInfos
-                                        then Executable s fb (buildInfos !! (length buildInfos - 1))
-                                        else Executable s fb (buildInfos !! bii)) exes'
+                                        then Executable (T.unpack s) fb (buildInfos !! (length buildInfos - 1))
+                                        else Executable (T.unpack s) fb (buildInfos !! bii)) exes'
             tests = map (\ (Test' s fb bii) -> if bii + 1 > length buildInfos
-                                        then TestSuite s fb (buildInfos !! (length buildInfos - 1)) False
-                                        else TestSuite s fb (buildInfos !! bii) False) tests'
+                                        then TestSuite (T.unpack s) fb (buildInfos !! (length buildInfos - 1)) False
+                                        else TestSuite (T.unpack s) fb (buildInfos !! bii) False) tests'
             bms = map (\ (Benchmark' s fb bii) -> if bii + 1 > length buildInfos
-                                        then Benchmark s fb (buildInfos !! (length buildInfos - 1)) False
-                                        else Benchmark s fb (buildInfos !! bii) False) benchmarks'
+                                        then Benchmark (T.unpack s) fb (buildInfos !! (length buildInfos - 1)) False
+                                        else Benchmark (T.unpack s) fb (buildInfos !! bii) False) benchmarks'
             mbLib = case mbLib' of
                     Nothing -> Nothing
                     Just (Library' mn b bii) -> if bii + 1 > length buildInfos
@@ -526,11 +533,11 @@
 
 toEditor :: PackageDescription -> PackageDescriptionEd
 toEditor pd =
-    let     (exes,exeBis) = unzip $ map (\((Executable s fb bi), i) -> ((Executable' s fb i), bi))
+    let     (exes,exeBis) = unzip $ map (\((Executable s fb bi), i) -> ((Executable' (T.pack s) fb i), bi))
                             (zip (executables pd) [0..])
-            (tests,testBis) = unzip $ map (\((TestSuite s fb bi _), i) -> ((Test' s fb i), bi))
+            (tests,testBis) = unzip $ map (\((TestSuite s fb bi _), i) -> ((Test' (T.pack s) fb i), bi))
                             (zip (testSuites pd) [length exeBis..])
-            (bms,benchmarkBis) = unzip $ map (\((Benchmark s fb bi _), i) -> ((Benchmark' s fb i), bi))
+            (bms,benchmarkBis) = unzip $ map (\((Benchmark s fb bi _), i) -> ((Benchmark' (T.pack s) fb i), bi))
                             (zip (benchmarks pd) [length testBis..])
             bis = exeBis ++ testBis ++ benchmarkBis
             (mbLib,bis2) = case library pd of
@@ -639,7 +646,7 @@
     closeB  <- buttonNewFromStock "gtk-close"
     addB    <- buttonNewFromStock (__ "Add Build Info")
     removeB <- buttonNewFromStock (__ "Remove Build Info")
-    label   <-  labelNew Nothing
+    label   <-  labelNew (Nothing :: Maybe Text)
     boxPackStart bb addB PackNatural 0
     boxPackStart bb removeB PackNatural 0
     boxPackEnd bb closeB PackNatural 0
@@ -720,14 +727,14 @@
         let hasChanged = case mbP of
                                 Nothing -> False
                                 Just p -> p /= origPackageD
-        when (isJust mbP) $ labelSetMarkup label ""
+        when (isJust mbP) $ labelSetMarkup label ("" :: Text)
         when (isJust mbP) $ comparePDE (fromJust mbP) packageD
         markLabel nb (getTopWidget packagePane) hasChanged
         widgetSetSensitive save hasChanged
         return (e{gtkReturn=False}))
     registerEvent notifier ValidationError (\e -> do
         labelSetMarkup label $ "<span foreground=\"red\" size=\"x-large\">The following fields have invalid values: "
-            ++ eventText e ++ "</span>"
+            <> eventText e <> "</span>"
         return e)
     return (Just packagePane,[])
 
@@ -739,7 +746,7 @@
     -> FilePath
     -> [ModuleName]
     -> Int
-    -> [(String, FieldDescription PackageDescriptionEd)]
+    -> [(Text, FieldDescription PackageDescriptionEd)]
     -> FieldDescription PackageDescriptionEd
 packageDD packages fp modules numBuildInfos extras = NFD ([
     ((__ "Package"), VFD emptyParams [
@@ -761,8 +768,8 @@
                     $ paraShadow <<<- ParaShadow ShadowOut
                         $ paraMinSize <<<- ParaMinSize (-1,210)
                             $ emptyParams)
-            (description . pd)
-            (\ a b -> b{pd = (pd b){description = if null a then " " else a}})
+            (T.pack . description . pd)
+            (\ a b -> b{pd = (pd b){description = T.unpack $ if T.null a then " " else a}})
             multilineStringEditor
     ,   mkField
             (paraName <<<- ParaName (__ "Homepage") $ emptyParams)
@@ -914,8 +921,8 @@
             (customFieldsPD . pd)
             (\ a b -> b{pd = (pd b){customFieldsPD = a}})
             (multisetEditor
-                (ColumnDescr True [((__ "Name"),\(n,_) -> [cellText := n])
-                                   ,((__ "Value"),\(_,v) -> [cellText := v])])
+                (ColumnDescr True [((__ "Name"),\(n,_) -> [cellText := T.pack n])
+                                   ,((__ "Value"),\(_,v) -> [cellText := T.pack v])])
                 ((pairEditor
                     (stringxEditor (const True),emptyParams)
                     (stringEditor (const True) True,emptyParams)),emptyParams)
@@ -975,9 +982,9 @@
                         else bi)
         (zip bis [0..length bis - 1])
 
-buildInfoD :: Maybe FilePath -> [ModuleName] -> Int -> [(String,FieldDescription PackageDescriptionEd)]
+buildInfoD :: Maybe FilePath -> [ModuleName] -> Int -> [(Text,FieldDescription PackageDescriptionEd)]
 buildInfoD fp modules i = [
-    ((printf (__ "%s Build Info") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Build Info") (show (i + 1))), VFD emptyParams [
         mkField
             (paraName <<<- ParaName (__ "Component is buildable here") $ emptyParams)
             (buildable . (\a -> a !! i) . bis)
@@ -1004,13 +1011,13 @@
                         $ paraMinSize <<<- ParaMinSize (-1,300)
                             $ paraPack <<<- ParaPack PackGrow
                                 $ emptyParams)
-            (map display. otherModules . (\a -> a !! i) . bis)
+            (map (T.pack . display) . otherModules . (\a -> a !! i) . bis)
             (\ a b -> b{bis = update (bis b) i (\bi ->
-                bi{otherModules = (map (\i -> forceJust (simpleParse i)
+                bi{otherModules = (map (\i -> forceJust (simpleParse $ T.unpack i)
                 "   PackageEditor >> buildInfoD: no parse for moduile name" ) a)})})
             (modulesEditor modules)
     ]),
-    ((printf (__ "%s Compiler ") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Compiler ") (show (i + 1))), VFD emptyParams [
         mkField
             (paraName  <<<- ParaName (__ "Options for haskell compilers")
             $ paraDirection <<<- ParaDirection Vertical
@@ -1019,8 +1026,8 @@
             (options . (\a -> a !! i) . bis)
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{options = a})})
             (multisetEditor
-                (ColumnDescr True [( (__ "Compiler Flavor"),\(cv,_) -> [cellText := show cv])
-                                   ,( (__ "Options"),\(_,op) -> [cellText := concatMap (\s -> ' ' : s) op])])
+                (ColumnDescr True [( (__ "Compiler Flavor"),\(cv,_) -> [cellText := T.pack $ show cv])
+                                   ,( (__ "Options"),\(_,op) -> [cellText := T.pack $ concatMap (\s -> ' ' : s) op])])
                 ((pairEditor
                     (compilerFlavorEditor,emptyParams)
                     (optsEditor,emptyParams)),
@@ -1041,7 +1048,7 @@
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{ghcSharedOptions = a})})
             optsEditor
     ]),
-    ((printf (__ "%s Extensions ") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Extensions ") (show (i + 1))), VFD emptyParams [
         mkField
             (paraName  <<<- ParaName (__ "Extensions")
                 $ paraSynopsis  <<<- ParaSynopsis
@@ -1053,7 +1060,7 @@
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{oldExtensions = a})})
             extensionsEditor
     ]),
-    ((printf (__ "%s Build Tools ") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Build Tools ") (show (i + 1))), VFD emptyParams [
         mkField
             (paraName <<<- ParaName (__ "Tools needed for a build")
                 $ paraDirection <<<- ParaDirection Vertical
@@ -1063,7 +1070,7 @@
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{buildTools = a})})
             (dependenciesEditor [])
     ]),
-    ( (printf (__ "%s Pkg Config ") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Pkg Config ") (show (i + 1))), VFD emptyParams [
         mkField
             (paraName <<<- ParaName (__ "A list of pkg-config packages, needed to build this package")
                 $ paraDirection <<<- ParaDirection Vertical
@@ -1073,7 +1080,7 @@
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{pkgconfigDepends = a})})
             (dependenciesEditor [])
     ]),
-    ( (printf (__ "%s Opts C -1-") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Opts C -1-") (show (i + 1))), VFD emptyParams [
          mkField
             (paraName <<<- ParaName (__ "Options for C compiler")
                 $ paraDirection <<<- ParaDirection Vertical
@@ -1091,9 +1098,9 @@
     ,    mkField
             (paraName <<<- ParaName (__ "A list of header files to use when compiling")
                 $ paraDirection <<<- ParaDirection Vertical $ emptyParams)
-            (includes . (\a -> a !! i) . bis)
-            (\ a b -> b{bis = update (bis b) i (\bi -> bi{includes = a})})
-            (stringsEditor (const True) True)
+            (map T.pack . includes . (\a -> a !! i) . bis)
+            (\ a b -> b{bis = update (bis b) i (\bi -> bi{includes = map T.unpack a})})
+            (textsEditor (const True) True)
      ,   mkField
             (paraName <<<- ParaName (__ "A list of header files to install")
                 $ paraMinSize <<<- ParaMinSize (-1,150)
@@ -1102,7 +1109,7 @@
              (\ a b -> b{bis = update (bis b) i (\bi -> bi{installIncludes = a})})
            (filesEditor fp FileChooserActionOpen (__ "Select File"))
     ]),
-    ((printf (__ "%s Opts C -2-") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Opts C -2-") (show (i + 1))), VFD emptyParams [
          mkField
             (paraName <<<- ParaName (__ "A list of directories to search for header files")
                 $ paraMinSize <<<- ParaMinSize (-1,150)
@@ -1119,14 +1126,14 @@
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{cSources = a})})
             (filesEditor fp FileChooserActionOpen (__ "Select file"))
     ]),
-    ((printf (__ "%s Opts Libs ") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Opts Libs ") (show (i + 1))), VFD emptyParams [
          mkField
             (paraName <<<- ParaName (__ "A list of extra libraries to link with")
                 $ paraMinSize <<<- ParaMinSize (-1,150)
                     $ paraDirection <<<- ParaDirection Vertical $ emptyParams)
-            (extraLibs . (\a -> a !! i) . bis)
-            (\ a b -> b{bis = update (bis b) i (\bi -> bi{extraLibs = a})})
-            (stringsEditor (const True) True)
+            (map T.pack . extraLibs . (\a -> a !! i) . bis)
+            (\ a b -> b{bis = update (bis b) i (\bi -> bi{extraLibs = map T.unpack a})})
+            (textsEditor (const True) True)
      ,   mkField
             (paraName <<<- ParaName (__ "A list of directories to search for libraries.")
                 $ paraMinSize <<<- ParaMinSize (-1,150)
@@ -1135,7 +1142,7 @@
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{extraLibDirs = a})})
             (filesEditor fp FileChooserActionSelectFolder (__ "Select Folder"))
    ]),
-    ( (printf (__ "%s Other") (show (i + 1))), VFD emptyParams [
+    ((T.pack $ printf (__ "%s Other") (show (i + 1))), VFD emptyParams [
          mkField
             (paraName <<<- ParaName (__ "Options for C preprocessor")
                 $ paraDirection <<<- ParaDirection Vertical
@@ -1147,9 +1154,9 @@
             (paraName <<<- ParaName (__ "Support frameworks for Mac OS X")
                 $ paraMinSize <<<- ParaMinSize (-1,150)
                     $ paraDirection <<<- ParaDirection Vertical $ emptyParams)
-            (frameworks . (\a -> a !! i) . bis)
-            (\ a b -> b{bis = update (bis b) i (\bi -> bi{frameworks = a})})
-            (stringsEditor (const True) True)
+            (map T.pack . frameworks . (\a -> a !! i) . bis)
+            (\ a b -> b{bis = update (bis b) i (\bi -> bi{frameworks = map T.unpack a})})
+            (textsEditor (const True) True)
     ,   mkField
             (paraName <<<- ParaName (__ "Custom fields build info")
                 $ paraShadow <<<- ParaShadow ShadowIn
@@ -1158,8 +1165,8 @@
              (customFieldsBI . (\a -> a !! i) . bis)
             (\ a b -> b{bis = update (bis b) i (\bi -> bi{customFieldsBI = a})})
             (multisetEditor
-                (ColumnDescr True [((__ "Name"),\(n,_) -> [cellText := n])
-                                   ,((__ "Value"),\(_,v) -> [cellText := v])])
+                (ColumnDescr True [((__ "Name"),\(n,_) -> [cellText := T.pack n])
+                                   ,((__ "Value"),\(_,v) -> [cellText := T.pack v])])
                 ((pairEditor
                     (stringxEditor (const True),emptyParams)
                     (stringEditor (const True) True,emptyParams)),emptyParams)
@@ -1215,8 +1222,8 @@
 testedWithEditor :: Editor [(CompilerFlavor, VersionRange)]
 testedWithEditor para = do
     multisetEditor
-       (ColumnDescr True [((__ "Compiler Flavor"),\(cv,_) -> [cellText := show cv])
-                           ,((__ "Version Range"),\(_,vr) -> [cellText := display vr])])
+       (ColumnDescr True [((__ "Compiler Flavor"),\(cv,_) -> [cellText := T.pack $ show cv])
+                           ,((__ "Version Range"),\(_,vr) -> [cellText := T.pack $ display vr])])
        (pairEditor
             (compilerFlavorEditor, paraShadow <<<- (ParaShadow ShadowNone) $ emptyParams)
             (versionRangeEditor, paraShadow <<<- (ParaShadow ShadowNone) $ emptyParams),
@@ -1228,19 +1235,19 @@
 compilerFlavorEditor :: Editor CompilerFlavor
 compilerFlavorEditor para noti = do
     (wid,inj,ext) <- eitherOrEditor
-        (comboSelectionEditor flavors show, paraName <<<- (ParaName (__ "Select compiler")) $ emptyParams)
-        (stringEditor (\s -> not (null s)) True, paraName <<<- (ParaName (__ "Specify compiler")) $ emptyParams)
+        (comboSelectionEditor flavors (T.pack . show), paraName <<<- (ParaName (__ "Select compiler")) $ emptyParams)
+        (textEditor (\s -> not (T.null s)) True, paraName <<<- (ParaName (__ "Specify compiler")) $ emptyParams)
         (__ "Other")
         (paraName <<<- ParaName (__ "Select") $ para)
         noti
     let cfinj comp  = case comp of
-                        (OtherCompiler str) -> inj (Right str)
+                        (OtherCompiler str) -> inj (Right $ T.pack str)
                         other               -> inj (Left other)
     let cfext = do
         mbp <- ext
         case mbp of
             Nothing -> return Nothing
-            Just (Right s) -> return (Just $OtherCompiler s)
+            Just (Right s) -> return (Just . OtherCompiler $ T.unpack s)
             Just (Left other) -> return (Just other)
     return (wid,cfinj,cfext)
         where
@@ -1249,34 +1256,30 @@
 buildTypeEditor :: Editor BuildType
 buildTypeEditor para noti = do
     (wid,inj,ext) <- eitherOrEditor
-        (comboSelectionEditor flavors show, paraName <<<- (ParaName (__ "Select")) $ emptyParams)
-        (stringEditor (const True) True, paraName <<<- (ParaName (__ "Unknown")) $ emptyParams)
+        (comboSelectionEditor flavors (T.pack . show), paraName <<<- (ParaName (__ "Select")) $ emptyParams)
+        (textEditor (const True) True, paraName <<<- (ParaName (__ "Unknown")) $ emptyParams)
         (__ "Unknown")
         (paraName <<<- ParaName (__ "Select") $ para)
         noti
     let cfinj comp  = case comp of
-                        (UnknownBuildType str) -> inj (Right str)
+                        (UnknownBuildType str) -> inj (Right $ T.pack str)
                         other               -> inj (Left other)
     let cfext = do
         mbp <- ext
         case mbp of
             Nothing -> return Nothing
-            Just (Right s) -> return (Just $ UnknownBuildType s)
+            Just (Right s) -> return (Just . UnknownBuildType $ T.unpack s)
             Just (Left other) -> return (Just other)
     return (wid,cfinj,cfext)
         where
         flavors = [Simple, Configure, Make, Custom]
 
 extensionsEditor :: Editor [Extension]
-extensionsEditor = staticListMultiEditor extensionsL show
+extensionsEditor = staticListMultiEditor extensionsL (T.pack . show)
 
 
 extensionsL :: [Extension]
-#if MIN_VERSION_Cabal(1,11,0)
 extensionsL = map EnableExtension [minBound..maxBound]
-#else
-extensionsL = knownExtensions
-#endif
 
 {--
 reposEditor :: Editor [SourceRepo]
@@ -1312,11 +1315,11 @@
     (widg,inj,ext) <- tupel7Editor
                             (repoKindEditor,noBorder)
                             (maybeEditor (repoTypeEditor,noBorder) True "Specify a type", emptyParams)
-                            (maybeEditor (stringEditor (const True) True,noBorder) True "Specify a location", emptyParams)
-                            (maybeEditor (stringEditor (const True) True,noBorder) True "Specify a module", emptyParams)
-                            (maybeEditor (stringEditor (const True) True,noBorder) True "Specify a branch", emptyParams)
-                            (maybeEditor (stringEditor (const True) True,noBorder) True "Specify a tag", emptyParams)
-                            (maybeEditor (stringEditor (const True) True,noBorder) True "Specify a subdir", emptyParams)
+                            (maybeEditor (textEditor (const True) True,noBorder) True "Specify a location", emptyParams)
+                            (maybeEditor (textEditor (const True) True,noBorder) True "Specify a module", emptyParams)
+                            (maybeEditor (textEditor (const True) True,noBorder) True "Specify a branch", emptyParams)
+                            (maybeEditor (textEditor (const True) True,noBorder) True "Specify a tag", emptyParams)
+                            (maybeEditor (textEditor (const True) True,noBorder) True "Specify a subdir", emptyParams)
                             (paraDirection  <<<- ParaDirection Vertical $ noBorder)
                             noti
     return (widg,
@@ -1336,7 +1339,7 @@
 repoKindEditor paras noti = do
     (widg,inj,ext) <- pairEditor
                         (comboSelectionEditor selectionList show, emptyParams)
-                        (stringEditor (const True) True,emptyParams)
+                        (textEditor (const True) True,emptyParams)
                         paras
                         noti
     return (widg,
@@ -1355,7 +1358,7 @@
 repoTypeEditor paras noti = do
     (widg,inj,ext) <- pairEditor
                         (comboSelectionEditor selectionList show, emptyParams)
-                        (stringEditor (const True) True,emptyParams)
+                        (textEditor (const True) True,emptyParams)
                         paras
                         noti
     return (widg,
@@ -1382,19 +1385,19 @@
     deriving (Show, Eq)
 
 data Executable' = Executable'{
-    exeName'        :: String
+    exeName'        :: Text
 ,   modulePath'     :: FilePath
 ,   buildInfoIdx    :: Int}
     deriving (Show, Eq)
 
 data Test' = Test'{
-    testName'        :: String
+    testName'        :: Text
 ,   testInterface'   :: TestSuiteInterface
 ,   testBuildInfoIdx :: Int}
     deriving (Show, Eq)
 
 data Benchmark' = Benchmark'{
-    benchmarkName'        :: String
+    benchmarkName'        :: Text
 ,   benchmarkInterface'   :: BenchmarkInterface
 ,   benchmarkBuildInfoIdx :: Int}
     deriving (Show, Eq)
@@ -1429,28 +1432,25 @@
             (paraDirection <<<- ParaDirection Vertical
             $ emptyParams)
             noti
-    let pinj (Library' em exp bi) = inj (exp, map display em,bi)
+    let pinj (Library' em exp bi) = inj (exp, map (T.pack . display) em,bi)
     let pext = do
         mbp <- ext
         case mbp of
             Nothing -> return Nothing
-            Just (exp,em,bi) -> return (Just $ Library' (map (\s -> forceJust (simpleParse s)
+            Just (exp,em,bi) -> return (Just $ Library' (map (\s -> forceJust (simpleParse $ T.unpack s)
                 "SpecialEditor >> libraryEditor: no parse for moduile name") em) exp bi)
     return (wid,pinj,pext)
 
---moduleEditor :: [ModuleName] -> Editor String
---moduleEditor modules    =   comboSelectionEditor (map display modules)
-
-modulesEditor :: [ModuleName] -> Editor [String]
-modulesEditor modules   =   staticListMultiEditor (map display modules) id
+modulesEditor :: [ModuleName] -> Editor [Text]
+modulesEditor modules   =   staticListMultiEditor (map (T.pack . display) modules) id
 
 executablesEditor :: Maybe FilePath -> [ModuleName] -> Int -> Editor [Executable']
 executablesEditor fp modules countBuildInfo p =
     multisetEditor
         (ColumnDescr True [( (__ "Executable Name"),\(Executable' exeName _ _) -> [cellText := exeName])
-                           ,( (__ "Module Path"),\(Executable'  _ mp _) -> [cellText := mp])
+                           ,( (__ "Module Path"),\(Executable'  _ mp _) -> [cellText := T.pack mp])
 
-                           ,( (__ "Build info index"),\(Executable'  _ _ bii) -> [cellText := show (bii + 1)])])
+                           ,( (__ "Build info index"),\(Executable'  _ _ bii) -> [cellText := T.pack $ show (bii + 1)])])
         (executableEditor fp modules countBuildInfo,emptyParams)
         Nothing
         Nothing
@@ -1460,7 +1460,7 @@
 executableEditor :: Maybe FilePath -> [ModuleName] -> Int -> Editor Executable'
 executableEditor fp modules countBuildInfo para noti = do
     (wid,inj,ext) <- tupel3Editor
-        (stringEditor (\s -> not (null s)) True,
+        (textEditor (\s -> not (T.null s)) True,
             paraName <<<- ParaName (__ "Executable Name")
             $ emptyParams)
         (stringEditor (\s -> not (null s)) True,
@@ -1487,8 +1487,8 @@
 testsEditor fp modules countBuildInfo p =
     multisetEditor
         (ColumnDescr True [( (__ "Test Name"),\(Test' testName _ _) -> [cellText := testName])
-                           ,( (__ "Interface"),\(Test'  _ i _) -> [cellText := interfaceName i])
-                           ,( (__ "Build info index"),\(Test'  _ _ bii) -> [cellText := show (bii + 1)])])
+                           ,( (__ "Interface"),\(Test'  _ i _) -> [cellText := T.pack $ interfaceName i])
+                           ,( (__ "Build info index"),\(Test'  _ _ bii) -> [cellText := T.pack $ show (bii + 1)])])
         (testEditor fp modules countBuildInfo,emptyParams)
         Nothing
         Nothing
@@ -1501,7 +1501,7 @@
 testEditor :: Maybe FilePath -> [ModuleName] -> Int -> Editor Test'
 testEditor fp modules countBuildInfo para noti = do
     (wid,inj,ext) <- tupel3Editor
-        (stringEditor (\s -> not (null s)) True,
+        (textEditor (\s -> not (T.null s)) True,
             paraName <<<- ParaName (__ "Test Name")
             $ emptyParams)
         (stringEditor (\s -> not (null s)) True,
@@ -1529,8 +1529,8 @@
 benchmarksEditor fp modules countBuildInfo p =
     multisetEditor
         (ColumnDescr True [( (__ "Benchmark Name"),\(Benchmark' benchmarkName _ _) -> [cellText := benchmarkName])
-                           ,( (__ "Interface"),\(Benchmark'  _ i _) -> [cellText := interfaceName i])
-                           ,( (__ "Build info index"),\(Benchmark'  _ _ bii) -> [cellText := show (bii + 1)])])
+                           ,( (__ "Interface"),\(Benchmark'  _ i _) -> [cellText := T.pack $ interfaceName i])
+                           ,( (__ "Build info index"),\(Benchmark'  _ _ bii) -> [cellText := T.pack $ show (bii + 1)])])
         (benchmarkEditor fp modules countBuildInfo,emptyParams)
         Nothing
         Nothing
@@ -1543,7 +1543,7 @@
 benchmarkEditor :: Maybe FilePath -> [ModuleName] -> Int -> Editor Benchmark'
 benchmarkEditor fp modules countBuildInfo para noti = do
     (wid,inj,ext) <- tupel3Editor
-        (stringEditor (\s -> not (null s)) True,
+        (textEditor (\s -> not (T.null s)) True,
             paraName <<<- ParaName (__ "Benchmark Name")
             $ emptyParams)
         (stringEditor (\s -> not (null s)) True,
diff --git a/src/IDE/Pane/PackageFlags.hs b/src/IDE/Pane/PackageFlags.hs
--- a/src/IDE/Pane/PackageFlags.hs
+++ b/src/IDE/Pane/PackageFlags.hs
@@ -1,5 +1,9 @@
-{-# LANGUAGE FlexibleInstances, ScopedTypeVariables, DeriveDataTypeable,
-             MultiParamTypeClasses, TypeSynonymInstances, Rank2Types #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.PackageFlags
@@ -44,6 +48,10 @@
 import Debug.Trace (trace)
 import IDE.Utils.GUIUtils (__)
 import Control.Monad (void)
+import Data.Text (Text)
+import Data.Monoid ((<>))
+import qualified Data.Text as T (unwords, unpack, pack)
+import Control.Applicative ((<$>))
 
 data IDEFlags               =   IDEFlags {
     flagsBox                ::   VBox
@@ -134,7 +142,7 @@
 getFlags (Just pp)  = forceGetPane (Left pp)
 
 quoteArg :: String -> String
-quoteArg s | ' ' `elem` s = "\"" ++ escapeQuotes s ++ "\""
+quoteArg s | ' ' `elem` s = "\"" <> escapeQuotes s <> "\""
 quoteArg s = s
 
 escapeQuotes = foldr (\c s -> if c == '"' then '\\':c:s else c:s) ""
@@ -147,28 +155,28 @@
         noneOf "\"")
     <?> "argsParser"
 
-argParser :: CharParser () String
+argParser :: CharParser () Text
 argParser = try (do
         char '"'
         s <- many quotedArgCharParser
         char '"'
-        return s)
+        return $ T.pack s)
     <|> try (
-        many1 (noneOf " "))
+        T.pack <$> many1 (noneOf " "))
     <?> "argParser"
 
-argsParser :: CharParser () [String]
+argsParser :: CharParser () [Text]
 argsParser = try (
         many (do
             many (char ' ')
             argParser))
     <?> "argsParser"
 
-unargs :: [String] -> String
-unargs = unwords . map quoteArg
+unargs :: [Text] -> Text
+unargs = T.unwords . map (T.pack . quoteArg . T.unpack)
 
-args :: String -> [String]
-args s = case parse argsParser "" s of
+args :: Text -> [Text]
+args s = case parse argsParser "" $ T.unpack s of
             Right result -> result
             _ -> [s]
 
@@ -183,7 +191,7 @@
             readParser
             (unargs . ipdConfigFlags)
             (\ b a -> a{ipdConfigFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ -> return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Build flags") $ emptyParams)
@@ -191,7 +199,7 @@
             readParser
             (unargs . ipdBuildFlags)
             (\ b a -> a{ipdBuildFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->  return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Test flags") $ emptyParams)
@@ -199,7 +207,7 @@
             readParser
             (unargs . ipdTestFlags)
             (\ b a -> a{ipdTestFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->   return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Haddock flags") $ emptyParams)
@@ -207,7 +215,7 @@
             readParser
             (unargs . ipdHaddockFlags)
             (\ b a -> a{ipdHaddockFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->   return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Executable flags") $ emptyParams)
@@ -215,7 +223,7 @@
             readParser
             (unargs . ipdExeFlags)
             (\ b a -> a{ipdExeFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->   return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Install flags") $ emptyParams)
@@ -223,7 +231,7 @@
             readParser
             (unargs . ipdInstallFlags)
             (\ b a -> a{ipdInstallFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->   return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Register flags") $ emptyParams)
@@ -231,7 +239,7 @@
             readParser
             (unargs . ipdRegisterFlags)
             (\ b a -> a{ipdRegisterFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->   return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Unregister flags") $ emptyParams)
@@ -239,7 +247,7 @@
             readParser
             (unargs . ipdUnregisterFlags)
             (\ b a -> a{ipdUnregisterFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ ->   return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Source Distribution flags") $ emptyParams)
@@ -247,7 +255,7 @@
             readParser
             (unargs . ipdSdistFlags)
             (\ b a -> a{ipdSdistFlags = args b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\ _ -> return ())]
 
 -- ------------------------------------------------------------
diff --git a/src/IDE/Pane/Preferences.hs b/src/IDE/Pane/Preferences.hs
--- a/src/IDE/Pane/Preferences.hs
+++ b/src/IDE/Pane/Preferences.hs
@@ -1,5 +1,9 @@
-{-# LANGUAGE CPP, FlexibleInstances, ScopedTypeVariables, DeriveDataTypeable,
-             MultiParamTypeClasses, TypeSynonymInstances #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Preferences
@@ -76,6 +80,10 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad (void, forM_, when)
 import System.FilePath ((</>))
+import Data.Text (Text)
+import qualified Data.Text as T (isSuffixOf, unpack, pack, null)
+import Data.Monoid ((<>))
+import Control.Applicative ((<$>))
 
 -- ---------------------------------------------------------------------
 -- This needs to be incremented, when the preferences format changes
@@ -127,7 +135,7 @@
             (widget,injb,ext,notifier) <-  buildEditor
                                 (extractFieldDescription $ prefsDescription configDir packageInfos) prefs
             boxPackStart vb widget PackGrow 0
-            label   <-  labelNew Nothing
+            label   <-  labelNew (Nothing :: Maybe Text)
             boxPackStart vb label PackNatural 0
             boxPackEnd vb bb PackNatural 5
             let prefsPane = IDEPrefs vb
@@ -194,13 +202,13 @@
                                         Nothing -> False
                                         Just p -> p{prefsFormat = 0, prefsSaveTime = ""} /=
                                                   prefs{prefsFormat = 0, prefsSaveTime = ""}
-                when (isJust mbP) $ labelSetMarkup label ""
+                when (isJust mbP) $ labelSetMarkup label ("" :: Text)
                 markLabel nb (getTopWidget prefsPane) hasChanged
                 widgetSetSensitive save hasChanged
                 return (e{gtkReturn=False}))
             registerEvent notifier ValidationError (\e -> do
                 labelSetMarkup label $ "<span foreground=\"red\" size=\"x-large\">The following fields have invalid values: "
-                    ++ eventText e ++ "</span>"
+                    <> eventText e <> "</span>"
                 return e)
             return (Just prefsPane,[])
 
@@ -250,7 +258,7 @@
             (paraName <<<- ParaName (__ "TextView Font") $ emptyParams)
             (\a -> PP.text (case a of Nothing -> show ""; Just s -> show s))
             (do str <- stringParser
-                return (if null str then Nothing else Just str))
+                return (if T.null str then Nothing else Just str))
             textviewFont
             (\ b a -> a{textviewFont = b})
             fontEditor
@@ -318,7 +326,7 @@
             (PP.text . show)
             readParser
             sourceCandy (\b a -> a{sourceCandy = b})
-            (disableEditor (stringEditor (not . null) True,
+            (disableEditor (textEditor (not . T.null) True,
                 paraName <<<- ParaName (__ "Candy specification")
                                     $ emptyParams)
                     True (__ "Use it ?"))
@@ -333,7 +341,7 @@
             (paraName <<<- ParaName (__ "Editor Style") $ emptyParams)
             (\a -> PP.text (case a of (False,_) -> show ""; (True, s) -> show s))
             (do str <- stringParser
-                return (if null str then (False, __ "classic") else (True,str)))
+                return (if T.null str then (False, __ "classic") else (True,str)))
             sourceStyle
             (\b a -> a{sourceStyle = b})
             styleEditor
@@ -418,8 +426,8 @@
             (paraName <<<- ParaName (__ "Text Editor") $ emptyParams)
             (PP.text . show)
             stringParser
-            textEditor
-            (\b a -> a{textEditor = b})
+            textEditorType
+            (\b a -> a{textEditorType = b})
             (comboSelectionEditor ["GtkSourceView", "Yi", "CodeMirror"] id)
             (\i -> return ())
     ]),
@@ -428,7 +436,7 @@
             (paraName <<<- ParaName (__ "LogView Font") $ emptyParams)
             (\a -> PP.text (case a of Nothing -> show ""; Just s -> show s))
             (do str <- stringParser
-                return (if null str then Nothing else Just str))
+                return (if T.null str then Nothing else Just str))
             logviewFont
             (\ b a -> a{logviewFont = b})
             fontEditor
@@ -470,11 +478,11 @@
                 $ paraSynopsis <<<- ParaSynopsis
                     (__ "The name of a keymap file in a config dir")
                     $ paraDirection <<<- ParaDirection Horizontal $ emptyParams)
-            PP.text
+            (PP.text . T.unpack)
             identifier
             keymapName
             (\b a -> a{keymapName = b})
-            (stringEditor (not . null) True)
+            (textEditor (not . T.null) True)
             (\ a -> return ())
     ]),
     (__ "Initial Pane positions", VFDPP emptyParams [
@@ -493,8 +501,8 @@
                 (ColumnDescr True [(__ "Pane Id", \ (n, _) -> [cellText := n])
                                    ,(__ "Pane Category", \ (_, v) -> [cellText := v])])
                 (pairEditor
-                    (stringEditor (not . null) True, emptyParams)
-                    (stringEditor (not . null) True, emptyParams), emptyParams)
+                    (textEditor (not . T.null) True, emptyParams)
+                    (textEditor (not . T.null) True, emptyParams), emptyParams)
                 (Just (sortBy (\(a,_) (a2,_) -> compare a a2)))
                 (Just (\(a,_) (a2,_) -> a == a2)))
             (\i -> return ())
@@ -511,8 +519,8 @@
             (\b a -> a{pathForCategory = b})
             (multisetEditor
                 (ColumnDescr True [(__ "Pane category", \ (n, _) -> [cellText := n])
-                                   ,(__ "Pane path", \ (_, v) -> [cellText := show v])])
-                (pairEditor (stringEditor (not . null) True, emptyParams)
+                                   ,(__ "Pane path", \ (_, v) -> [cellText := T.pack $ show v])])
+                (pairEditor (textEditor (not . T.null) True, emptyParams)
                     (genericEditor, emptyParams),
                   emptyParams)
                 (Just (sortBy (\(a,_) (a2,_) -> compare a a2)))
@@ -553,7 +561,7 @@
             stringParser
             retrieveURL
             (\b a -> a{retrieveURL = b})
-            (stringEditor (const True) True)
+            (textEditor (const True) True)
             (\i -> return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Strategy for downloading prebuilt metadata") $ emptyParams)
@@ -587,7 +595,7 @@
             stringParser
             serverIP
             (\b a -> a{serverIP = b})
-            (stringEditor (not . null) True)
+            (textEditor (not . T.null) True)
             (\i -> return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "Stop the leksah-server process when leksah disconnects") $ emptyParams)
@@ -729,30 +737,30 @@
             stringParser
             browser
             (\b a -> a{browser = b})
-            (stringEditor (not . null) True)
+            (textEditor (not . T.null) True)
             (\i -> return ())
     ,   mkFieldPP
             (paraName <<<- ParaName (__ "URL for searching documentation") $
                 paraSynopsis <<<- ParaSynopsis
-                    ("e.g Hoogle: http://www.haskell.org/hoogle/?q= or " ++
+                    ("e.g Hoogle: http://www.haskell.org/hoogle/?q= or " <>
                         "Hayoo: http://holumbus.fh-wedel.de/hayoo/hayoo.html?query=")
                         $ emptyParams)
             (PP.text . show)
             stringParser
             docuSearchURL
             (\b a -> a{docuSearchURL = b})
-            (stringEditor (not . null) True)
+            (textEditor (not . T.null) True)
             (\i -> return ())
     ])]
 
 
-styleEditor :: Editor (Bool, String)
+styleEditor :: Editor (Bool, Text)
 styleEditor p n = do
     styleManager <- sourceStyleSchemeManagerNew
     dataDir <- getDataDir
     sourceStyleSchemeManagerAppendSearchPath styleManager $ dataDir </> "data/styles"
     ids          <- sourceStyleSchemeManagerGetSchemeIds styleManager
-    let notDarkIds = filter (not . isSuffixOf "-dark") ids
+    let notDarkIds = filter (not . T.isSuffixOf "-dark") ids
     disableEditor (comboSelectionEditor notDarkIds id, p) True (__ "Select a special style?") p n
 
 
@@ -773,7 +781,7 @@
     ,   matchBackground     =   Color 32768 32768 32768
     ,   contextBackground   =   Color 65535 49152 49152
     ,   breakpointBackground =  Color 65535 49152 32768
-    ,   textEditor          =   "GtkSourceView"
+    ,   textEditorType      =   "GtkSourceView"
     ,   autoLoad            =   False
     ,   logviewFont         =   Nothing
     ,   defaultSize         =   (1024,800)
@@ -838,9 +846,9 @@
 readPrefs fn = catch (do
     configDir <- getConfigDir
     readFields fn (flattenFieldDescriptionPPToS (prefsDescription configDir [])) defaultPrefs)
-	(\ (e :: SomeException) -> do
-		sysMessage Normal (show e)
-		return defaultPrefs)
+        (\ (e :: SomeException) -> do
+            sysMessage Normal (T.pack $ show e)
+            return defaultPrefs)
 -- ------------------------------------------------------------
 -- * Printing
 -- ------------------------------------------------------------
@@ -849,7 +857,7 @@
 writePrefs fpath prefs = do
     timeNow         <- liftIO getClockTime
     configDir <- getConfigDir
-    let newPrefs    =   prefs {prefsSaveTime = show timeNow, prefsFormat = prefsVersion}
+    let newPrefs    =   prefs {prefsSaveTime = T.pack $ show timeNow, prefsFormat = prefsVersion}
     writeFields fpath newPrefs (flattenFieldDescriptionPPToS (prefsDescription configDir []))
 
 
diff --git a/src/IDE/Pane/Search.hs b/src/IDE/Pane/Search.hs
--- a/src/IDE/Pane/Search.hs
+++ b/src/IDE/Pane/Search.hs
@@ -1,5 +1,8 @@
-{-# LANGUAGE FlexibleInstances, DeriveDataTypeable, MultiParamTypeClasses,
-             TypeSynonymInstances, ScopedTypeVariables #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Search
@@ -63,6 +66,8 @@
 import System.Glib.Properties (newAttrFromMaybeStringProperty)
 import Control.Monad (void)
 import Graphics.UI.Gtk.General.Enums (ShadowType(..))
+import Data.Text (Text)
+import qualified Data.Text as T (pack, null)
 
 -- | A search pane description
 --
@@ -77,12 +82,12 @@
 ,   entry           ::   Entry
 ,   scopeSelection  ::   Scope -> IDEAction
 ,   modeSelection   ::   SearchMode -> IDEAction
-,   searchMetaGUI   ::   String -> IDEAction
+,   searchMetaGUI   ::   Text -> IDEAction
 ,   setChoices     ::   [Descr] -> IDEAction
 } deriving Typeable
 
 data SearchState    =   SearchState {
-    searchString    ::   String
+    searchString    ::   Text
 ,   searchScope     ::   Scope
 ,   searchMode      ::   SearchMode
 }   deriving(Eq,Ord,Read,Show,Typeable)
@@ -178,11 +183,11 @@
         cellLayoutSetAttributes col1 renderer1 listStore
             $ \row -> [ cellText := case dsMbModu row of
                                         Nothing -> ""
-                                        Just pm -> display $ modu pm]
+                                        Just pm -> T.pack . display $ modu pm]
         cellLayoutSetAttributes col1 renderer10 listStore
             $ \row -> [newAttrFromMaybeStringProperty "stock-id"
                          := if isReexported row
-                                    then Just "ide_reexported"
+                                    then Just ("ide_reexported" :: Text)
                                         else if isJust (dscMbLocation row)
                                             then Just "ide_source"
                                             else Nothing]
@@ -198,7 +203,7 @@
         cellLayoutSetAttributes col2 renderer2 listStore
             $ \row -> [ cellText := case dsMbModu row of
                                         Nothing -> ""
-                                        Just pm -> display $ pack pm]
+                                        Just pm -> T.pack . display $ pack pm]
 
         renderer3   <- cellRendererTextNew
         col3        <- treeViewColumnNew
@@ -209,7 +214,7 @@
         treeViewAppendColumn treeView col3
         cellLayoutPackStart col3 renderer3 True
         cellLayoutSetAttributes col3 renderer3 listStore
-            $ \row -> [ cellText := BS.unpack $ fromMaybe BS.empty $
+            $ \row -> [ cellText := T.pack . BS.unpack . fromMaybe BS.empty $
                             dscMbTypeStr row,
                         cellTextScale := 0.8, cellTextScaleSet := True    ]
 
@@ -244,14 +249,14 @@
                 liftIO $ writeIORef (searchModeRef search) mode
                 text   <- liftIO $ entryGetText entry
                 searchMetaGUI_ text
-            searchMetaGUI_ :: String -> IDEAction
+            searchMetaGUI_ :: Text -> IDEAction
             searchMetaGUI_ str = do
                 liftIO $ bringPaneToFront search
                 liftIO $ entrySetText entry str
                 scope  <- liftIO $ getScope search
                 mode   <- liftIO $ getMode search
             --    let mode' = if length str > 2 then mode else Exact (caseSense mode)
-                descrs <- if null str
+                descrs <- if T.null str
                             then return []
                             else searchMeta scope str mode
                 liftIO $ do
@@ -377,7 +382,7 @@
 --        otherwise       ->  return ()
 
 {--
-launchSymbolNavigationDialog :: String -> (Descr -> IDEM ()) -> IDEM ()
+launchSymbolNavigationDialog :: Text -> (Descr -> IDEM ()) -> IDEM ()
 launchSymbolNavigationDialog txt act = do
     dia                        <-   liftIO $ dialogNew
     win <- getMainWindow
diff --git a/src/IDE/Pane/SourceBuffer.hs b/src/IDE/Pane/SourceBuffer.hs
--- a/src/IDE/Pane/SourceBuffer.hs
+++ b/src/IDE/Pane/SourceBuffer.hs
@@ -1,5 +1,11 @@
-{-# LANGUAGE FlexibleInstances, DeriveDataTypeable, MultiParamTypeClasses,
-             CPP, TypeSynonymInstances, ScopedTypeVariables, RankNTypes #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# OPTIONS_GHC -fwarn-unused-imports #-}
 -----------------------------------------------------------------------------
 --
@@ -23,6 +29,7 @@
 ,   maybeActiveBuf
 ,   selectSourceBuf
 ,   goToSourceDefinition
+,   goToSourceDefinition'
 ,   goToDefinition
 ,   insertInBuffer
 ,   replaceHLintSource
@@ -100,8 +107,6 @@
 import Data.IORef (writeIORef,readIORef,newIORef)
 import Control.Event (triggerEvent)
 import IDE.Metainfo.Provider (getSystemInfo, getWorkspaceInfo)
-import Distribution.Text (simpleParse)
-import Distribution.ModuleName (ModuleName)
 import Graphics.UI.Gtk
        (Notebook, clipboardGet, selectionClipboard, dialogAddButton, widgetDestroy,
         fileChooserGetFilename, widgetShow, fileChooserDialogNew,
@@ -133,6 +138,12 @@
 import qualified IDE.Command.Print as Print
 import Control.Monad.Trans.Class (MonadTrans(..))
 import System.Log.Logger (debugM)
+import Data.Text (Text)
+import qualified Data.Text as T
+       (length, findIndex, replicate, lines, dropWhileEnd, unlines, strip,
+        null, pack, unpack)
+import Data.Monoid ((<>))
+import qualified Data.Text.IO as T (writeFile, readFile)
 
 allBuffers :: MonadIDE m => m [IDEBuffer]
 allBuffers = liftIDE getPanes
@@ -150,7 +161,7 @@
                                     return (Just (BufferStateTrans (bufferName p) text offset))
                                 Just fn ->  return (Just (BufferState fn offset))
     recoverState pp (BufferState n i) =   do
-        mbbuf    <-  newTextBuffer pp (takeFileName n) (Just n)
+        mbbuf    <-  newTextBuffer pp (T.pack $ takeFileName n) (Just n)
         case mbbuf of
             Just (IDEBuffer {sourceView=v}) -> do
                 ideR    <- ask
@@ -230,29 +241,38 @@
                     prefs <- readIDE prefs
                     pp      <- getBestPathForId  "*Buffer"
                     liftIO $ debugM "lekash" "selectSourceBuf calling newTextBuffer"
-                    nbuf <- newTextBuffer pp (takeFileName fpc) (Just fpc)
+                    nbuf <- newTextBuffer pp (T.pack $ takeFileName fpc) (Just fpc)
                     liftIO $ debugM "lekash" "selectSourceBuf newTextBuffer returned"
                     return nbuf
                 else do
-                    ideMessage Normal ((__ "File path not found ") ++ fpc)
+                    ideMessage Normal ((__ "File path not found ") <> T.pack fpc)
                     return Nothing
 
 goToDefinition :: Descr -> IDEAction
 goToDefinition idDescr  = do
+
     mbWorkspaceInfo     <-  getWorkspaceInfo
     mbSystemInfo        <-  getSystemInfo
-    let mbSourcePath1   =   case mbWorkspaceInfo of
-                                    Nothing -> Nothing
-                                    Just (sc, _) -> sourcePathFromScope sc
-    let mbSourcePath2   =   case mbSourcePath1 of
-                                Just sp -> Just sp
-                                Nothing -> case mbSystemInfo of
-                                                Just si -> sourcePathFromScope si
-                                                Nothing -> Nothing
-    when (isJust mbSourcePath2) $
-        goToSourceDefinition (fromJust $ mbSourcePath2) (dscMbLocation idDescr) >> return ()
-    return ()
-    where
+    let mbPackagePath = (mbWorkspaceInfo >>= (packagePathFromScope . fst))
+                        <|> (mbSystemInfo >>= packagePathFromScope)
+        mbSourcePath = (mbWorkspaceInfo  >>= (sourcePathFromScope . fst))
+                        <|> (mbSystemInfo >>= sourcePathFromScope)
+
+    liftIO . debugM "leksah" $ show (mbPackagePath, dscMbLocation idDescr, mbSourcePath)
+    case (mbPackagePath, dscMbLocation idDescr, mbSourcePath) of
+        (Just packagePath, Just loc, _) -> goToSourceDefinition (dropFileName packagePath) loc >> return ()
+        (_, Just loc, Just sourcePath)  -> goToSourceDefinition' sourcePath loc >> return ()
+        (_, _, Just sp) -> selectSourceBuf sp >> return ()
+        _  -> return ()
+  where
+    packagePathFromScope :: GenScope -> Maybe FilePath
+    packagePathFromScope (GenScopeC (PackScope l _)) =
+        case dscMbModu idDescr of
+            Just mod -> case (pack mod) `Map.lookup` l of
+                            Just pack -> pdMbSourcePath pack
+                            Nothing   -> Nothing
+            Nothing -> Nothing
+
     sourcePathFromScope :: GenScope -> Maybe FilePath
     sourcePathFromScope (GenScopeC (PackScope l _)) =
         case dscMbModu idDescr of
@@ -265,35 +285,38 @@
                             Nothing -> Nothing
             Nothing -> Nothing
 
-goToSourceDefinition :: FilePath -> Maybe Location -> IDEM (Maybe IDEBuffer)
-goToSourceDefinition fp dscMbLocation = do
---    liftIO $ putStrLn $ "goToSourceDefinition " ++ fp
-    mbBuf     <- selectSourceBuf fp
-    when (isJust mbBuf && isJust dscMbLocation) $
-        inActiveBufContext () $ \_ sv ebuf _ _ -> do
-            let location    =   fromJust dscMbLocation
-            liftIO $ debugM "lekash" "goToSourceDefinition calculating range"
-            lines           <-  getLineCount ebuf
-            iterTemp        <-  getIterAtLine ebuf (max 0 (min (lines-1)
-                                    ((locationSLine location) -1)))
-            chars           <-  getCharsInLine iterTemp
-            iter <- atLineOffset iterTemp (max 0 (min (chars-1) (locationSCol location -1)))
-            iter2Temp       <-  getIterAtLine ebuf (max 0 (min (lines-1)
-                                    ((locationELine location) -1)))
-            chars2          <-  getCharsInLine iter2Temp
-            iter2 <- atLineOffset iter2Temp (max 0 (min (chars2-1) (locationECol location)))
-            -- ### we had a problem before using this idleAdd thing
-            ideR <- ask
-            liftIO . (`idleAdd` priorityDefaultIdle) . (`reflectIDE` ideR) $ do
-                liftIO $ debugM "lekash" "goToSourceDefinition triggered selectRange"
-                selectRange ebuf iter iter2
-                liftIO $ debugM "lekash" "goToSourceDefinition triggered scrollToIter"
-                scrollToIter sv iter 0.0 (Just (0.3,0.3))
-                return False
-            return ()
+goToSourceDefinition :: FilePath -> Location -> IDEM (Maybe IDEBuffer)
+goToSourceDefinition packagePath loc = do
+    goToSourceDefinition' (packagePath </> locationFile loc) loc
+
+goToSourceDefinition' :: FilePath -> Location -> IDEM (Maybe IDEBuffer)
+goToSourceDefinition' sourcePath Location{..} = do
+    mbBuf     <- selectSourceBuf sourcePath
+    case mbBuf of
+        Just buf -> do
+            inActiveBufContext () $ \_ sv ebuf _ _ -> do
+                liftIO $ debugM "lekash" "goToSourceDefinition calculating range"
+                lines           <-  getLineCount ebuf
+                iterTemp        <-  getIterAtLine ebuf (max 0 (min (lines-1)
+                                        (locationSLine -1)))
+                chars           <-  getCharsInLine iterTemp
+                iter <- atLineOffset iterTemp (max 0 (min (chars-1) (locationSCol -1)))
+                iter2Temp       <-  getIterAtLine ebuf (max 0 (min (lines-1) (locationELine -1)))
+                chars2          <-  getCharsInLine iter2Temp
+                iter2 <- atLineOffset iter2Temp (max 0 (min (chars2-1) locationECol))
+                -- ### we had a problem before using this idleAdd thing
+                ideR <- ask
+                liftIO . (`idleAdd` priorityDefaultIdle) . (`reflectIDE` ideR) $ do
+                    liftIO $ debugM "lekash" "goToSourceDefinition triggered selectRange"
+                    selectRange ebuf iter iter2
+                    liftIO $ debugM "lekash" "goToSourceDefinition triggered scrollToIter"
+                    scrollToIter sv iter 0.0 (Just (0.3,0.3))
+                    return False
+                return ()
+        Nothing -> return ()
     return mbBuf
 
-replaceHLintSource :: FilePath -> Int -> Int -> Int -> Int -> String -> IDEAction
+replaceHLintSource :: FilePath -> Int -> Int -> Int -> Int -> Text -> IDEAction
 replaceHLintSource file lineS columnS lineE columnE to = do
     mbBuf     <- selectSourceBuf file
     case mbBuf of
@@ -340,8 +363,8 @@
     contextRefs <- readIDE contextRefs
     prefs       <- readIDE prefs
     inBufContext () buf $ \_ sv ebuf buf _ -> do
-        let tagName = (show $ logRefType logRef) ++ show index
-        liftIO . debugM "lekash" $ "markRefInSourceBuf getting or creating tag " ++ tagName
+        let tagName = T.pack $ show (logRefType logRef) ++ show index
+        liftIO . debugM "lekash" . T.unpack $ "markRefInSourceBuf getting or creating tag " <> tagName
         tagTable <- getTagTable ebuf
         mbTag <- lookupTag tagTable tagName
         case mbTag of
@@ -406,7 +429,7 @@
                 return False
             return ()
 
-newTextBuffer :: PanePath -> String -> Maybe FilePath -> IDEM (Maybe IDEBuffer)
+newTextBuffer :: PanePath -> Text -> Maybe FilePath -> IDEM (Maybe IDEBuffer)
 newTextBuffer panePath bn mbfn = do
     cont <- case mbfn of
                 Nothing -> return True
@@ -420,7 +443,7 @@
             (ind,rbn) <- figureOutPaneName bn 0
             buildThisPane panePath nb (builder' bs mbfn ind bn rbn ct prefs)
         else do
-            ideMessage Normal ((__ "File does not exist ") ++ (fromJust mbfn))
+            ideMessage Normal ((__ "File does not exist ") <> (T.pack $ fromJust mbfn))
             return Nothing
 
 data CharacterCategory = IdentifierCharacter | SpaceCharacter | SyntaxCharacter
@@ -435,8 +458,8 @@
 builder' :: Bool ->
     Maybe FilePath ->
     Int ->
-    String ->
-    String ->
+    Text ->
+    Text ->
     CandyTable ->
     Prefs ->
     PanePath ->
@@ -447,12 +470,12 @@
     -- load up and display a file
     (fileContents,modTime) <- case mbfn of
         Just fn -> do
-            fc <- liftIO $ UTF8.readFile fn
+            fc <- liftIO $ T.readFile fn
             mt <- liftIO $ getModificationTime fn
             return (fc,Just mt)
         Nothing -> return ("\n",Nothing)
 
-    case textEditor prefs  of
+    case textEditorType prefs of
         "GtkSourceView" -> newGtkBuffer mbfn fileContents >>= makeBuffer modTime
         "Yi"            -> newYiBuffer mbfn fileContents >>= makeBuffer modTime
         "CodeMirror"    -> newCMBuffer mbfn fileContents >>= makeBuffer modTime
@@ -547,10 +570,10 @@
                             (si1,si2)   <- getSelectionBounds ebuf
 
                             sTxt      <- getCandylessPart candy' ebuf si1 si2
-                            let strippedSTxt = strip' sTxt
-                            case strippedSTxt of
-                                [] -> return ()
-                                _  -> do
+                            let strippedSTxt = T.strip sTxt
+                            if T.null strippedSTxt
+                                then return ()
+                                else do
                                     bi1 <- getStartIter ebuf
                                     bi2 <- getEndIter ebuf
                                     forwardApplying bi1 strippedSTxt (Just si1) tagName ebuf
@@ -613,31 +636,18 @@
             createHyperLinkSupport sv sw (\ctrl shift iter -> do
                 (beg, en) <- getIdentifierUnderCursorFromIter (iter, iter)
                 return (beg, if ctrl then en else beg)) (\_ shift' slice -> do
-                            when (slice /= []) $ do
+                            unless (T.null slice) $ do
                                 -- liftIO$ print ("slice",slice)
                                 triggerEventIDE (SelectInfo slice shift')
                                 return ()
                             )
         return (Just buf,concat [ids1, ids2, ids3, ids4, ids5, ids6, ids7])
-    wschars' :: String
-    wschars' = " \t\r\n"
 
-    strip' :: String -> String
-    strip' = lstrip' . rstrip'
-
-    lstrip' :: String -> String
-    lstrip' s = case s of
-                    [] -> []
-                    (x:xs) -> if elem x wschars'
-                              then lstrip' xs
-                              else s
-    rstrip' :: String -> String
-    rstrip' = reverse . lstrip' . reverse
     forwardApplying :: TextEditor editor
                     => EditorIter editor
-                    -> String   -- txt
+                    -> Text   -- txt
                     -> Maybe (EditorIter editor)
-                    -> String   -- tagname
+                    -> Text   -- tagname
                     -> EditorBuffer editor
                     -> IDEM ()
     forwardApplying tI txt mbTi tagName ebuf = do
@@ -720,7 +730,7 @@
                                         load <- readIDE (autoLoad . prefs)
                                         if load
                                             then do
-                                                ideMessage Normal $ (__ "Auto Loading ") ++ fn
+                                                ideMessage Normal $ (__ "Auto Loading ") <> T.pack fn
                                                 revert buf
                                                 return (False, True)
                                             else do
@@ -730,7 +740,7 @@
                                                             (Just window) []
                                                             MessageQuestion
                                                             ButtonsNone
-                                                            ((__"File \"") ++ name ++ (__ "\" has changed on disk."))
+                                                            ((__"File \"") <> name <> (__ "\" has changed on disk."))
                                                     dialogAddButton md (__ "_Load From Disk") (ResponseUser 1)
                                                     dialogAddButton md (__ "_Always Load From Disk") (ResponseUser 2)
                                                     dialogAddButton md (__ "_Don't Load") (ResponseUser 3)
@@ -766,7 +776,7 @@
                 nmt <- getModificationTime fn
                 writeIORef (modTime buf) (Just nmt))
             (\(e:: SomeException) -> do
-                sysMessage Normal (show e)
+                sysMessage Normal (T.pack $ show e)
                 return ())
 
 fileRevert :: IDEAction
@@ -785,7 +795,7 @@
             fc <- liftIO $ UTF8.readFile fn
             mt <- liftIO $ getModificationTime fn
             beginNotUndoableAction buffer
-            setText buffer fc
+            setText buffer $ T.pack fc
             if useCandy
                 then modeTransformToCandy (mode buf)
                          (modeEditInCommentOrString (mode buf)) buffer
@@ -904,7 +914,7 @@
                                             nb ideBuf useCandy candy fn
                                         closePane ideBuf
                                         cfn <- liftIO $ myCanonicalizePath fn
-                                        newTextBuffer panePath (takeFileName cfn) (Just cfn)
+                                        newTextBuffer panePath (T.pack $ takeFileName cfn) (Just cfn)
                                         ) ideR
                                     return True
                                 _          -> return False
@@ -914,16 +924,14 @@
             buf     <-   getBuffer $ sv
             text    <-   getCandylessText candyTable buf
             let text' = if removeTBlanks
-                            then unlines $ map removeTrailingBlanks $lines text
+                            then T.unlines $ map (T.dropWhileEnd $ \c -> c == ' ') $ T.lines text
                             else text
-            succ <- liftIO $ E.catch (do UTF8.writeFile fn text'; return True)
+            succ <- liftIO $ E.catch (do T.writeFile fn text'; return True)
                 (\(e :: SomeException) -> do
-                    sysMessage Normal (show e)
+                    sysMessage Normal . T.pack $ show e
                     return False)
             setModified buf (not succ)
             markLabelAsChanged nb ideBuf
-        removeTrailingBlanks :: String -> String
-        removeTrailingBlanks = reverse . dropWhile (\c -> c == ' ') . reverse
 
 fileSave :: Bool -> IDEM Bool
 fileSave query = inActiveBufContext False $ fileSaveBuffer query
@@ -978,8 +986,8 @@
                                             MessageQuestion
                                             ButtonsCancel
                                             ((__ "Save changes to document: ")
-                                                ++ paneName currentBuffer
-                                                ++ "?")
+                                                <> paneName currentBuffer
+                                                <> "?")
                 dialogAddButton md (__ "_Save") ResponseYes
                 dialogAddButton md (__ "_Don't Save") ResponseNo
                 set md [ windowWindowPosition := WinPosCenterOnParent ]
@@ -1127,7 +1135,7 @@
     where
         reallyOpen prefs fpc =   do
             pp <-  getBestPathForId "*Buffer"
-            newTextBuffer pp (takeFileName fpc) (Just fpc)
+            newTextBuffer pp (T.pack $ takeFileName fpc) (Just fpc)
             return ()
 
 filePrint :: IDEAction
@@ -1141,11 +1149,11 @@
                 md <- messageDialogNew (Just window) []
                                             MessageQuestion
                                             ButtonsNone
-                                            ("Print document: "
-                                                ++ pName
-                                                ++ "?")
-                dialogAddButton md "_Print" ResponseYes
-                dialogAddButton md "_Don't Print" ResponseNo
+                                            (__"Print document: "
+                                                <> pName
+                                                <> "?")
+                dialogAddButton md (__"_Print") ResponseYes
+                dialogAddButton md (__"_Don't Print") ResponseNo
                 set md [ windowWindowPosition := WinPosCenterOnParent ]
                 resp <- dialogRun md
                 widgetDestroy md
@@ -1166,12 +1174,12 @@
                         md <- messageDialogNew (Just window) []
                                                     MessageQuestion
                                                     ButtonsNone
-                                                    ("Save changes to document: "
-                                                        ++ pName
-                                                        ++ "?")
-                        dialogAddButton md "_Save" ResponseYes
-                        dialogAddButton md "_Don't Save" ResponseNo
-                        dialogAddButton md "_Cancel Printing" ResponseCancel
+                                                    (__"Save changes to document: "
+                                                        <> pName
+                                                        <> "?")
+                        dialogAddButton md (__"_Save") ResponseYes
+                        dialogAddButton md (__"_Don't Save") ResponseNo
+                        dialogAddButton md (__"_Cancel Printing") ResponseCancel
                         set md [ windowWindowPosition := WinPosCenterOnParent ]
                         resp <- dialogRun md
                         widgetDestroy md
@@ -1191,7 +1199,7 @@
                         Just name -> do
                                       status <- liftIO $ Print.print name
                                       case status of
-                                        Left error -> liftIO $ showDialog (show error) MessageError
+                                        Left error -> liftIO $ showDialog (T.pack $ show error) MessageError
                                         Right _ -> liftIO $ showDialog "Print job has been sent successfully" MessageInfo
                                       return ()
                         Nothing   -> return ()
@@ -1237,7 +1245,7 @@
 editShiftLeft :: IDEAction
 editShiftLeft = do
     prefs <- readIDE prefs
-    let str = map (\_->' ') [1 .. (tabWidth prefs)]
+    let str = T.replicate (tabWidth prefs) " "
     b <- canShiftLeft str prefs
     if b
         then do
@@ -1260,7 +1268,7 @@
 editShiftRight :: IDEAction
 editShiftRight = do
     prefs <- readIDE prefs
-    let str = map (\_->' ') [1 .. (tabWidth prefs)]
+    let str = T.replicate (tabWidth prefs) " "
     doForSelectedLines [] $ \ebuf lineNr -> do
         sol <- getIterAtLine ebuf lineNr
         insert ebuf sol str
@@ -1279,7 +1287,7 @@
             sol <- getIterAtLine ebuf lineNr
             eol <- forwardToLineEndC sol
             line  <- getText ebuf sol eol True
-            return (lineNr, elemIndex char line)
+            return (lineNr, T.findIndex (==char) line)
     alignChar :: Map Int (Maybe Int) -> Int -> IDEM ()
     alignChar positions alignTo = do
             doForSelectedLines [] $ \ebuf lineNr -> do
@@ -1287,7 +1295,7 @@
                     Just (Just n)  ->  do
                         sol       <- getIterAtLine ebuf lineNr
                         insertLoc <- forwardCharsC sol n
-                        insert ebuf insertLoc (replicate (alignTo - n) ' ')
+                        insert ebuf insertLoc (T.replicate (alignTo - n) " ")
                     _              ->  return ()
             return ()
 
@@ -1320,7 +1328,7 @@
         triggerEventIDE UpdateRecent
         return ()
 
-selectedText :: IDEM (Maybe String)
+selectedText :: IDEM (Maybe Text)
 selectedText = do
     candy' <- readIDE candy
     inActiveBufContext Nothing $ \_ _ ebuf currentBuffer _ -> do
@@ -1332,7 +1340,7 @@
                 return $ Just text
             else return Nothing
 
-selectedTextOrCurrentLine :: IDEM (Maybe String)
+selectedTextOrCurrentLine :: IDEM (Maybe Text)
 selectedTextOrCurrentLine = do
     candy' <- readIDE candy
     inActiveBufContext Nothing $ \_ _ ebuf currentBuffer _ -> do
@@ -1360,7 +1368,7 @@
             else return (line, lineOffset)
         return $ Just res
 
-insertTextAfterSelection :: String -> IDEAction
+insertTextAfterSelection :: Text -> IDEAction
 insertTextAfterSelection str = do
     candy'       <- readIDE candy
     inActiveBufContext () $ \_ _ ebuf currentBuffer _ -> do
@@ -1372,7 +1380,7 @@
             mark       <- createMark ebuf i True
             insert ebuf i realString
             i1         <- getIterAtMark ebuf mark
-            i2         <- forwardCharsC i1 (length str)
+            i2         <- forwardCharsC i1 (T.length str)
             selectRange ebuf i1 i2
 
 -- | Returns the package, to which this buffer belongs, if possible
diff --git a/src/IDE/Pane/Trace.hs b/src/IDE/Pane/Trace.hs
--- a/src/IDE/Pane/Trace.hs
+++ b/src/IDE/Pane/Trace.hs
@@ -53,11 +53,15 @@
 import Control.Monad.Trans.Class (MonadTrans(..))
 import Control.Monad.IO.Class (MonadIO(..))
 import IDE.Utils.GUIUtils (treeViewContextMenu, __)
-import Text.Printf (printf)
 import Data.Text (Text)
 import Data.Monoid ((<>))
-import qualified Data.Text as T (unpack)
+import qualified Data.Text as T (pack, unpack)
+import qualified Text.Printf as S (printf)
+import Text.Printf (PrintfType)
 
+printf :: PrintfType r => Text -> r
+printf = S.printf . T.unpack
+
 -- | A debugger pane description
 --
 data IDETrace    =   IDETrace {
@@ -72,7 +76,7 @@
 data TraceHist = TraceHist {
     thSelected      ::  Bool,
     thIndex         ::  Int,
-    thFunction      ::  String,
+    thFunction      ::  Text,
     thPosition      ::  SrcSpan
     }
 
@@ -109,7 +113,7 @@
 
     renderer0 <- cellRendererToggleNew
     col0         <- treeViewColumnNew
-    treeViewColumnSetTitle col0 ""
+    treeViewColumnSetTitle col0 (""::Text)
     treeViewColumnSetSizing col0 TreeViewColumnAutosize
     treeViewColumnSetResizable col0 False
     treeViewColumnSetReorderable col0 True
@@ -127,7 +131,7 @@
     treeViewAppendColumn treeView col1
     cellLayoutPackStart col1 renderer1 False
     cellLayoutSetAttributes col1 renderer1 tracepoints
-        $ \row -> [ cellText := show (thIndex row)]
+        $ \row -> [ cellText := T.pack $ show (thIndex row)]
 
     renderer2    <- cellRendererTextNew
     col2         <- treeViewColumnNew
@@ -149,7 +153,7 @@
     treeViewAppendColumn treeView col3
     cellLayoutPackStart col3 renderer3 False
     cellLayoutSetAttributes col3 renderer3 tracepoints
-        $ \row -> [ cellText := displaySrcSpan (thPosition row)]
+        $ \row -> [ cellText := T.pack $ displaySrcSpan (thPosition row)]
 
     treeViewSetHeadersVisible treeView True
     sel <- treeViewGetSelection treeView
@@ -239,24 +243,24 @@
 tracesParser :: CharParser () [TraceHist]
 tracesParser = try (do
         whiteSpace
-        symbol (__ "Empty history.")
+        symbol (T.unpack $ __ "Empty history.")
         skipMany anyChar
         eof
         return [])
     <|> do
         traces <- many (try traceParser)
         whiteSpace
-        symbol (__ "<end of history>")
+        symbol (T.unpack $ __ "<end of history>")
         eof
         return traces
     <|> do
         whiteSpace
-        symbol (__ "Not stopped at a breakpoint")
+        symbol (T.unpack $ __ "Not stopped at a breakpoint")
         skipMany anyChar
         eof
         return []
     <?>
-        __ "traces parser"
+        (T.unpack $ __ "traces parser")
 
 traceParser :: CharParser () TraceHist
 traceParser = do
@@ -264,13 +268,13 @@
     index    <- int
     colon
     optional (symbol "\ESC[1m")
-    function <- many (noneOf "(\ESC")
+    function <- T.pack <$> many (noneOf "(\ESC")
     optional (symbol "\ESC[0m")
     symbol "("
     span     <- srcSpanParser
     symbol ")"
     return (TraceHist False index function span)
-    <?> __ "trace parser"
+    <?> (T.unpack $ __ "trace parser")
 
 lexer  = P.makeTokenParser emptyDef
 colon  = P.colon lexer
diff --git a/src/IDE/Pane/Variables.hs b/src/IDE/Pane/Variables.hs
--- a/src/IDE/Pane/Variables.hs
+++ b/src/IDE/Pane/Variables.hs
@@ -53,7 +53,8 @@
 import IDE.Utils.GUIUtils (treeViewContextMenu, __)
 import Data.Text (Text)
 import Data.Monoid ((<>))
-import qualified Data.Text as T (unpack)
+import qualified Data.Text as T (pack, unpack)
+import Control.Applicative ((<$>))
 
 -- | A variables pane description
 --
@@ -64,9 +65,9 @@
 } deriving Typeable
 
 data VarDescription = VarDescription {
-    varName         ::  String
-,   varType         ::  String
-,   varValue        ::  String}
+    varName         ::  Text
+,   varType         ::  Text
+,   varValue        ::  Text}
 
 data VariablesState  =   VariablesState {
 }   deriving(Eq,Ord,Read,Show,Typeable)
@@ -162,7 +163,7 @@
             to <- CL.consume
             liftIO $ postGUIAsync $
                 case parse variablesParser "" . T.unpack $ selectString to of
-                    Left e -> sysMessage Normal (show e)
+                    Left e -> sysMessage Normal (T.pack $ show e)
                     Right triples -> do
                         treeStoreClear (variables var)
                         mapM_ (insertBreak (variables var))
@@ -179,7 +180,7 @@
             to <- CL.consume
             liftIO $ postGUIAsync $
                 case parse variablesParser "" . T.unpack $ selectString to of
-                    Left e -> sysMessage Normal (show e)
+                    Left e -> sysMessage Normal (T.pack $ show e)
                     Right triples -> do
                         treeStoreClear (variables var)
                         mapM_ (insertBreak (variables var))
@@ -214,11 +215,11 @@
 variableParser :: CharParser () VarDescription
 variableParser = do
     whiteSpace
-    varName <- many (noneOf ":")
+    varName <- T.pack <$> many (noneOf ":")
     symbol "::"
-    typeStr  <- many (noneOf "=")
+    typeStr  <- T.pack <$> many (noneOf "=")
     char '='
-    value <- many (
+    value <- T.pack <$> many (
         noneOf "\n"
         <|> try (do
                 r <- char '\n'
@@ -228,20 +229,20 @@
     return (VarDescription varName typeStr value)
     <?> "variableParser"
 
-valueParser :: CharParser () String
+valueParser :: CharParser () Text
 valueParser = do
     whiteSpace
     many (noneOf "=")
     char '='
-    many anyChar
+    T.pack <$> many anyChar
     <?> "valueParser"
 
-typeParser :: CharParser () String
+typeParser :: CharParser () Text
 typeParser = do
     whiteSpace
     many (noneOf ":")
     symbol "::"
-    many anyChar
+    T.pack <$> many anyChar
     <?> "typeParser"
 
 
@@ -285,38 +286,38 @@
 
 forceVariable :: VarDescription -> TreePath -> TreeStore VarDescription -> IDEAction
 forceVariable varDescr path treeStore = packageTry $ tryDebug $ do
-    debugCommand' (":force " ++ varName varDescr) $ do
+    debugCommand' (":force " <> varName varDescr) $ do
         to <- CL.consume
         liftIO $ postGUIAsync $
             case parse valueParser "" . T.unpack $ selectString to of
-                Left e -> sysMessage Normal (show e)
+                Left e -> sysMessage Normal (T.pack $ show e)
                 Right value -> do
                     var <- treeStoreGetValue treeStore path
                     treeStoreSetValue treeStore path var{varValue = value}
-    debugCommand' (":type " ++ varName varDescr) $ do
+    debugCommand' (":type " <> varName varDescr) $ do
         to <- CL.consume
         liftIO $ postGUIAsync $
             case parse typeParser "" . T.unpack $ selectString to of
-                Left e -> sysMessage Normal (show e)
+                Left e -> sysMessage Normal (T.pack $ show e)
                 Right typ -> do
                     var <- treeStoreGetValue treeStore path
                     treeStoreSetValue treeStore path var{varType = typ}
 
 printVariable :: VarDescription -> TreePath -> TreeStore VarDescription -> IDEAction
 printVariable varDescr path treeStore = packageTry $ tryDebug $ do
-    debugCommand' (":print " ++ varName varDescr) $ do
+    debugCommand' (":print " <> varName varDescr) $ do
         to <- CL.consume
         liftIO $ postGUIAsync $
             case parse valueParser "" . T.unpack $ selectString to of
-                Left e -> sysMessage Normal (show e)
+                Left e -> sysMessage Normal (T.pack $ show e)
                 Right value -> do
                     var <- treeStoreGetValue treeStore path
                     treeStoreSetValue treeStore path var{varValue = value}
-    debugCommand' (":type " ++ varName varDescr) $ do
+    debugCommand' (":type " <> varName varDescr) $ do
         to <- CL.consume
         liftIO $ postGUIAsync $
             case parse typeParser "" . T.unpack $ selectString to of
-                Left e -> sysMessage Normal (show e)
+                Left e -> sysMessage Normal (T.pack $ show e)
                 Right typ -> do
                     var <- treeStoreGetValue treeStore path
                     treeStoreSetValue treeStore path var{varType = typ}
diff --git a/src/IDE/Pane/WebKit/Documentation.hs b/src/IDE/Pane/WebKit/Documentation.hs
--- a/src/IDE/Pane/WebKit/Documentation.hs
+++ b/src/IDE/Pane/WebKit/Documentation.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.WebKit.Documentation
@@ -32,6 +33,7 @@
        (scrolledWindowSetShadowType, scrolledWindowSetPolicy,
         scrolledWindowNew, castToWidget, ScrolledWindow)
 import Data.Typeable (Typeable)
+import Data.Text (Text)
 import IDE.Core.Types (IDEAction, IDEM)
 import Control.Monad.IO.Class (MonadIO(..))
 import Graphics.UI.Frame.ViewFrame (getNotebook)
@@ -67,7 +69,7 @@
 
 data DocumentationState = DocumentationState {
     zoom :: Float
-  , uri  :: Maybe String
+  , uri  :: Maybe Text
 } deriving(Eq,Ord,Read,Show,Typeable)
 
 instance Pane IDEDocumentation IDEM
@@ -137,7 +139,7 @@
 getDocumentation Nothing    = forceGetPane (Right "*Doc")
 getDocumentation (Just pp)  = forceGetPane (Left pp)
 
-loadDoc :: String -> IDEAction
+loadDoc :: Text -> IDEAction
 loadDoc uri = do
 #ifdef WEBKITGTK
     doc <- getDocumentation Nothing
diff --git a/src/IDE/Pane/WebKit/Output.hs b/src/IDE/Pane/WebKit/Output.hs
--- a/src/IDE/Pane/WebKit/Output.hs
+++ b/src/IDE/Pane/WebKit/Output.hs
@@ -1,9 +1,10 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE TypeSynonymInstances #-}
 {-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.WebKit.Output
@@ -33,6 +34,7 @@
         boxPackStart, entrySetText, Entry, VBox, entryNew, vBoxNew,
         postGUISync, scrolledWindowSetPolicy, scrolledWindowNew,
         castToWidget, ScrolledWindow)
+import IDE.Utils.GUIUtils
 import Data.Typeable (Typeable)
 import IDE.Core.Types (IDEAction, IDEM, IDE(..))
 import Control.Monad.IO.Class (MonadIO(..))
@@ -68,6 +70,8 @@
 import Graphics.UI.Gtk.WebKit.WebView
        (loadCommitted, webViewGetUri)
 import Graphics.UI.Gtk.WebKit.WebFrame (webFrameGetUri)
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, pack)
 
 data IDEOutput = IDEOutput {
     vbox          :: VBox
@@ -117,7 +121,7 @@
     builder pp nb windows = reifyIDE $ \ ideR -> do
         vbox <- vBoxNew False 0
         uriEntry <- entryNew
-        entrySetText uriEntry "http://"
+        entrySetText uriEntry ("http://" :: Text)
         scrolledView <- scrolledWindowNew Nothing Nothing
         scrolledWindowSetShadowType scrolledView ShadowIn
         boxPackStart vbox uriEntry PackNatural 0
@@ -151,7 +155,7 @@
 
         cid3 <- on webView populatePopup $ \ menu -> do
             alwaysHtml <- readIORef alwaysHtmlRef
-            action <- toggleActionNew "AlwaysHTML" "Always HTML" Nothing Nothing
+            action <- toggleActionNew "AlwaysHTML" (__"Always HTML") Nothing Nothing
             item <- castToMenuItem <$> actionCreateMenuItem action
             item `on` menuItemActivate $ writeIORef alwaysHtmlRef $ not alwaysHtml
             toggleActionSetActive action alwaysHtml
@@ -188,28 +192,28 @@
 getOutputPane Nothing    = forceGetPane (Right "*Out")
 getOutputPane (Just pp)  = forceGetPane (Left pp)
 
-getValueUri :: IO String
+getValueUri :: IO Text
 getValueUri = do
     dataDir <- leksahOrPackageDir "pretty-show" getDataDir
-    return $ "file://"
+    return . T.pack $ "file://"
         ++ (case dataDir of
                 ('/':_) -> dataDir
                 _       -> '/':dataDir)
         ++ "/value.html"
 
-setOutput :: String -> String -> IDEAction
+setOutput :: Text -> Text -> IDEAction
 setOutput command str = do
 #ifdef WEBKITGTK
     out <- getOutputPane Nothing
     liftIO $ do
-        entrySetText (uriEntry out) (show command)
+        entrySetText (uriEntry out) (T.pack $ show command)
         uri <- getValueUri
         alwaysHtml <- readIORef $ alwaysHtmlRef out
         let view = webView out
-            html = case (alwaysHtml, parseValue str) of
-                        (False, Just value) -> valToHtmlPage defaultHtmlOpts value
+            html = case (alwaysHtml, parseValue $ T.unpack str) of
+                        (False, Just value) -> T.pack $ valToHtmlPage defaultHtmlOpts value
                         _                   -> str
-        webViewLoadString view html Nothing Nothing uri
+        webViewLoadString view html Nothing uri
 #else
     return ()
 #endif
@@ -220,11 +224,11 @@
     out <- getOutputPane Nothing
     let view = webView out
     liftIO $ do
-        entrySetText (uriEntry out) uri
+        entrySetText (uriEntry out) (T.pack uri)
         currentUri <- webViewGetUri view
-        if Just uri == currentUri
+        if Just (T.pack uri) == currentUri
             then webViewReload view
-            else webViewLoadUri view uri
+            else webViewLoadUri view (T.pack uri)
 #else
     return ()
 #endif
diff --git a/src/IDE/Pane/Workspace.hs b/src/IDE/Pane/Workspace.hs
--- a/src/IDE/Pane/Workspace.hs
+++ b/src/IDE/Pane/Workspace.hs
@@ -1,5 +1,9 @@
-{-# LANGUAGE FlexibleInstances, ScopedTypeVariables, TypeSynonymInstances,
-             MultiParamTypeClasses, DeriveDataTypeable #-}
+{-# LANGUAGE DeriveDataTypeable #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Pane.Workspace
@@ -40,11 +44,13 @@
 import System.Log.Logger (debugM)
 import qualified Data.Function as F (on)
 import System.FilePath (takeDirectory, takeBaseName, takeFileName)
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
 
 -- | Workspace pane state
 --
 
-type WorkspaceRecord = (IDEPackage, Maybe String)
+type WorkspaceRecord = (IDEPackage, Maybe Text)
 
 data IDEWorkspace   =   IDEWorkspace {
     scrolledView        ::   ScrolledWindow
@@ -79,7 +85,7 @@
         treeViewSetModel treeView treeStore
 
         renderer0    <- cellRendererPixbufNew
-        set renderer0 [ newAttrFromMaybeStringProperty "stock-id"  := Nothing ]
+        set renderer0 [ newAttrFromMaybeStringProperty "stock-id"  := (Nothing :: Maybe Text) ]
 
         renderer1   <- cellRendererTextNew
         col1        <- treeViewColumnNew
@@ -107,7 +113,7 @@
         treeViewAppendColumn treeView col2
         cellLayoutPackStart col2 renderer2 True
         cellLayoutSetAttributes col2 renderer2 treeStore
-            $ \row -> [ cellText := file row ]
+            $ \row -> [ cellText := T.pack $ file row ]
 
         treeViewSetHeadersVisible treeView True
         sel <- treeViewGetSelection treeView
@@ -144,7 +150,7 @@
 
 getSelectionTree ::  TreeView
     -> TreeStore (Bool, WorkspaceRecord)
-    -> IO (Maybe (Bool, IDEPackage, Maybe String))
+    -> IO (Maybe (Bool, IDEPackage, Maybe Text))
 getSelectionTree treeView treeStore = do
     liftIO $ debugM "leksah" "getSelectionTree"
     treeSelection <- treeViewGetSelection treeView
diff --git a/src/IDE/PaneGroups.hs b/src/IDE/PaneGroups.hs
--- a/src/IDE/PaneGroups.hs
+++ b/src/IDE/PaneGroups.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.PaneGroups
diff --git a/src/IDE/Sandbox.hs b/src/IDE/Sandbox.hs
--- a/src/IDE/Sandbox.hs
+++ b/src/IDE/Sandbox.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Sandbox
@@ -20,15 +21,15 @@
 ) where
 
 import Graphics.UI.Gtk (Window)
+import Control.Applicative ((<$>), (<*>))
 import Control.Monad (when, void)
 import Control.Monad.Trans.Class (lift)
 import Control.Monad.IO.Class (liftIO)
 import Control.Monad.Trans.Reader (ask)
 import System.Exit (ExitCode(..))
 import System.FilePath (dropFileName)
-import qualified Data.Conduit as C (Sink)
+import qualified Data.Conduit as C (Sink, ZipSink(..), getZipSink)
 import qualified Data.Conduit.List as CL (fold)
-import qualified Data.Conduit.Util as CU (zipSinks)
 import IDE.Utils.Tool (ToolOutput(..))
 import IDE.Utils.GUIUtils (__, chooseDir)
 import IDE.Core.State (PackageAction, readIDE, prefs, ipdBuildDir, getMainWindow,
@@ -39,6 +40,8 @@
 import IDE.Pane.PackageEditor (choosePackageFile)
 import IDE.Workspaces (workspaceTryQuiet)
 import IDE.Package (refreshPackage)
+import Data.Monoid ((<>))
+import qualified Data.Text as T (pack)
 
 -- | Get the last item
 sinkLast = CL.fold (\_ a -> Just a) Nothing
@@ -46,7 +49,7 @@
 logSandbox :: IDEPackage -> LogLaunch -> C.Sink ToolOutput IDEM ()
 logSandbox package logLaunch = do
     let log = logOutput logLaunch
-    (mbLastOutput, _) <- CU.zipSinks sinkLast log
+    mbLastOutput <- C.getZipSink $ const <$> C.ZipSink sinkLast <*> C.ZipSink log
     when (mbLastOutput == Just (ToolExit ExitSuccess)) .
         lift $ workspaceTryQuiet (runPackage (void $ refreshPackage log) package)
 
@@ -72,7 +75,7 @@
         Just dir -> do
             logLaunch <- getDefaultLogLaunch
             runExternalTool' (__ "Sandbox Init")
-                "cabal" ["sandbox", "init", "--sandbox=" ++ dir]
+                "cabal" ["sandbox", "init", "--sandbox=" <> T.pack dir]
                 (ipdBuildDir package) (logSandbox package logLaunch)
 
 sandboxDelete :: PackageAction
@@ -98,6 +101,6 @@
         Just fp -> do
             logLaunch <- getDefaultLogLaunch
             runExternalTool' (__ "Sandbox Add Source")
-                "cabal" (["sandbox", "add-source", fp] ++ ["--snapshot" | snapshot])
+                "cabal" (["sandbox", "add-source", T.pack fp] ++ ["--snapshot" | snapshot])
                 (ipdBuildDir package) (logSandbox package logLaunch)
 
diff --git a/src/IDE/Session.hs b/src/IDE/Session.hs
--- a/src/IDE/Session.hs
+++ b/src/IDE/Session.hs
@@ -1,4 +1,6 @@
-{-# LANGUAGE CPP, ScopedTypeVariables #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Session
@@ -72,6 +74,8 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import Control.Monad (forM_, forM, when)
 import System.Log.Logger (debugM)
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
 
 -- ---------------------------------------------------------------------
 -- This needs to be incremented, when the session format changes
@@ -159,7 +163,7 @@
 
 data SessionState = SessionState {
         sessionVersion      ::   Int
-    ,   saveTime            ::   String
+    ,   saveTime            ::   Text
     ,   layoutS             ::   PaneLayout
     ,   population          ::   [(Maybe PaneState,PanePath)]
     ,   windowSize          ::   (Int,Int)
@@ -167,7 +171,7 @@
     ,   dark                ::   Bool
     ,   completionSize      ::   (Int,Int)
     ,   workspacePath       ::   Maybe FilePath
-    ,   activePaneN         ::   Maybe String
+    ,   activePaneN         ::   Maybe Text
     ,   toolbarVisibleS     ::   Bool
     ,   findbarState        ::   (Bool,FindState)
     ,   recentOpenedFiles   ::   [FilePath]
@@ -381,7 +385,7 @@
             recentWorkspaces' <- readIDE recentWorkspaces
             let state = SessionState {
                 sessionVersion      =   theSessionVersion
-            ,   saveTime            =   show timeNow
+            ,   saveTime            =   T.pack $ show timeNow
             ,   layoutS             =   layout
             ,   population          =   population
             ,   windowSize          =   size
@@ -530,7 +534,7 @@
             Just st -> return (Just (asPaneState st), fst v))
                 $ Map.toList paneMap
 
-getActive :: IDEM(Maybe String)
+getActive :: IDEM(Maybe FilePath)
 getActive = do
     active <- readIDE activePack
     case active of
@@ -582,7 +586,7 @@
         liftIO $ debugM "leksah" "recoverSession done"
         return (toolbarVisibleS sessionSt, (fst . findbarState) sessionSt))
         (\ (e :: SomeException) -> do
-            sysMessage Normal (show e)
+            sysMessage Normal (T.pack $ show e)
             return (True,True))
 
 applyLayout :: PaneLayout -> IDEAction
@@ -680,7 +684,7 @@
     case mbSettings of
         Just settings -> liftIO $ settingsSetLongProperty
                             settings
-                            "gtk-application-prefer-dark-theme"
+                            ("gtk-application-prefer-dark-theme" :: Text)
                             (if dark then 1 else 0)
                             "Leksah"
         Nothing -> return ()
diff --git a/src/IDE/SourceCandy.hs b/src/IDE/SourceCandy.hs
--- a/src/IDE/SourceCandy.hs
+++ b/src/IDE/SourceCandy.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.SourceCandy
@@ -18,10 +19,10 @@
 ,   transformToCandy    -- ::   TextBuffer -> IO ()
 ,   transformFromCandy  -- ::   TextBuffer -> IO ()
 ,   keystrokeCandy      -- ::   Maybe Char -> TextBuffer -> IO ()
-,   getCandylessText    -- ::   TextBuffer -> IO String
+,   getCandylessText    -- ::   TextBuffer -> IO Text
 
-,   getCandylessPart    -- ::   CandyTable -> TextBuffer -> TextIter -> TextIter -> IO String
-,   stringToCandy       -- ::   CandyTable -> String -> IO String
+,   getCandylessPart    -- ::   CandyTable -> TextBuffer -> TextIter -> TextIter -> IO Text
+,   stringToCandy       -- ::   CandyTable -> Text -> IO Text
 ,   positionToCandy     -- ::   CandyTable -> TextBuffer -> (Int,Int) -> IO (Int,Int)
 ,   positionFromCandy   -- ::   CandyTable -> TextBuffer -> (Int,Int) -> IO (Int,Int)
 ) where
@@ -38,6 +39,11 @@
 import IDE.Core.State
 import IDE.TextEditor
 import Control.Monad (unless)
+import Data.Text (Text)
+import qualified Data.Text as T
+       (pack, singleton, replicate, head, takeWhile, isSuffixOf, length,
+        index)
+import Data.Monoid ((<>))
 
 ---------------------------------------------------------------------------------
 -- * Implementation
@@ -48,7 +54,7 @@
                                     '^','|','-','~','\'','"']
 notAfterOp      =   notBeforeOp
 
-keystrokeCandy :: TextEditor editor => CandyTable -> Maybe Char -> EditorBuffer editor -> (String -> Bool) -> IDEM ()
+keystrokeCandy :: TextEditor editor => CandyTable -> Maybe Char -> EditorBuffer editor -> (Text -> Bool) -> IDEM ()
 keystrokeCandy (CT(transformTable,_)) mbc ebuf editInCommentOrString = do
     cursorMark  <-  getInsertMark ebuf
     endIter     <-  getIterAtMark ebuf cursorMark
@@ -65,12 +71,12 @@
     unless block $
         replace mbc2 cursorMark slice offset transformTable
     where
-    -- replace ::  Maybe Char -> m -> String -> Int -> [(Bool,String,String)] -> IDEM ()
+    -- replace ::  Maybe Char -> m -> Text -> Int -> [(Bool,Text,Text)] -> IDEM ()
     replace mbAfterChar cursorMark match offset list = replace' list
         where
         replace' [] = return ()
         replace' ((isOp,from,to):rest) =
-            let beforeChar  =  match !! (max 0 (length match - (length from + 1)))
+            let beforeChar  =  T.index match (max 0 (T.length match - (T.length from + 1)))
                 beforeOk    =  not $if isOp
                                     then Set.member beforeChar notBeforeOp
                                     else Set.member beforeChar notBeforeId
@@ -80,10 +86,10 @@
                                      not $if isOp
                                         then Set.member afterChar notAfterOp
                                         else Set.member afterChar notAfterId
-            in if isSuffixOf from match && beforeOk && afterOk
+            in if T.isSuffixOf from match && beforeOk && afterOk
                 then do
                     beginNotUndoableAction ebuf
-                    start   <-  getIterAtOffset ebuf (offset - (length from))
+                    start   <-  getIterAtOffset ebuf (offset - (T.length from))
                     end     <-  getIterAtOffset ebuf offset
                     delete ebuf start end
                     ins     <-   getIterAtMark ebuf cursorMark
@@ -91,7 +97,7 @@
                     endNotUndoableAction ebuf
                 else replace mbAfterChar cursorMark match offset rest
 
-transformToCandy :: TextEditor editor => CandyTable -> EditorBuffer editor -> (String -> Bool) -> IDEM ()
+transformToCandy :: TextEditor editor => CandyTable -> EditorBuffer editor -> (Text -> Bool) -> IDEM ()
 transformToCandy (CT(transformTable,_)) ebuf editInCommentOrString = do
     beginUserAction ebuf
     modified    <-  getModified ebuf
@@ -100,7 +106,7 @@
     endUserAction ebuf
 
 
-replaceTo :: TextEditor editor => EditorBuffer editor -> (Bool,String,String) -> Int -> (String -> Bool) -> IDEM ()
+replaceTo :: TextEditor editor => EditorBuffer editor -> (Bool,Text,Text) -> Int -> (Text -> Bool) -> IDEM ()
 replaceTo buf (isOp,from,to) offset editInCommentOrString = replaceTo' offset
     where
     replaceTo' offset = do
@@ -157,7 +163,7 @@
     endUserAction ebuf
     setModified ebuf modified
 
-getCandylessText :: TextEditor editor => CandyTable -> EditorBuffer editor -> IDEM String
+getCandylessText :: TextEditor editor => CandyTable -> EditorBuffer editor -> IDEM Text
 getCandylessText (CT(_,transformTableBack)) ebuf = do
     i1          <-  getStartIter ebuf
     i2          <-  getEndIter ebuf
@@ -169,7 +175,7 @@
     text2       <-  getText workBuffer i1 i2 True
     return text2
 
-getCandylessPart :: TextEditor editor => CandyTable -> EditorBuffer editor -> EditorIter editor -> EditorIter editor -> IDEM String
+getCandylessPart :: TextEditor editor => CandyTable -> EditorBuffer editor -> EditorIter editor -> EditorIter editor -> IDEM Text
 getCandylessPart (CT(_,transformTableBack)) ebuf i1 i2 = do
     text1       <-  getText ebuf i1 i2 True
     workBuffer  <-  simpleGtkBuffer text1
@@ -179,7 +185,7 @@
     text2       <-  getText workBuffer i1 i2 True
     return text2
 
-stringToCandy :: CandyTable -> String -> IDEM String
+stringToCandy :: CandyTable -> Text -> IDEM Text
 stringToCandy  candyTable text = do
     workBuffer  <-  simpleGtkBuffer text
     transformToCandy candyTable workBuffer (\ _ -> False)
@@ -215,7 +221,7 @@
     columnNew   <- getLineOffset i4
     return (line,columnNew)
 
-replaceFrom :: TextEditor editor => EditorBuffer editor -> (String,String,Int) -> Int -> IDEM ()
+replaceFrom :: TextEditor editor => EditorBuffer editor -> (Text,Text,Int) -> Int -> IDEM ()
 replaceFrom buf (to,from,spaces) offset = replaceFrom' offset
     where
     replaceFrom' offset = do
@@ -231,7 +237,7 @@
                         iter2 <-    getIterAtOffset buf offset
                         iter3 <-    getIterAtOffset buf (offset + spaces + 1)
                         slice <-    getSlice buf iter2 iter3 True
-                        let l = length (takeWhile (== ' ') slice)
+                        let l = T.length (T.takeWhile (== ' ') slice)
                         if l > 1
                             then do
                                 iter4 <- atOffset iter3 (offset + l - 1)
@@ -242,24 +248,24 @@
                 insert buf iter to
                 replaceFrom' offset
 
-type CandyTableI = [(String,Char,Bool)]
+type CandyTableI = [(Text,Char,Bool)]
 
 forthFromTable :: CandyTableI -> CandyTableForth
 forthFromTable table = map forthFrom table
     where
     forthFrom (str,chr,noTrimming) =
-        let isOp = not (Set.member (head str) notBeforeId)
+        let isOp = not (Set.member (T.head str) notBeforeId)
             from = str
-            trailingBlanks = replicate (if noTrimming then 0 else length str - 1) ' '
-            to = chr : trailingBlanks
+            trailingBlanks = T.replicate (if noTrimming then 0 else T.length str - 1) (T.singleton ' ')
+            to = T.singleton chr <> trailingBlanks
         in (isOp,from,to)
 
 backFromTable :: CandyTableI -> CandyTableBack
 backFromTable table = map backFrom table
     where
     backFrom (str,chr,noTrimming) =
-        let numTrailingBlanks = if noTrimming then 0 else length str - 1
-        in (str,[chr],numTrailingBlanks)
+        let numTrailingBlanks = if noTrimming then 0 else T.length str - 1
+        in (str,T.singleton chr,numTrailingBlanks)
 
 ---Candy Parser
 
@@ -280,7 +286,7 @@
 parseCandy fn = do
     res     <-  parseFromFile candyParser fn
     case res of
-        Left pe ->  throwIDE $"Error reading candy file " ++ show fn ++ " " ++ show pe
+        Left pe ->  throwIDE $ "Error reading candy file " <> T.pack (show fn) <> " " <> T.pack (show pe)
         Right r ->  return (CT(forthFromTable r, backFromTable r))
 
 candyParser :: CharParser () CandyTableI
@@ -290,7 +296,7 @@
     eof
     return ls
 
-oneCandyParser :: CharParser () (String,Char,Bool)
+oneCandyParser :: CharParser () (Text,Char,Bool)
 oneCandyParser = do
     toReplace   <-  toReplaceParser
     replaceWith <-  replaceWithParser
@@ -299,12 +305,12 @@
         return False)
     return (toReplace,replaceWith,nt)
 
-toReplaceParser :: CharParser () String
+toReplaceParser :: CharParser () Text
 toReplaceParser   = lexeme (do
     str         <-  between (char '"')
                         (char '"' <?> "end of string")
                         (many $noneOf "\"")
-    return str)
+    return $ T.pack str)
     <?> "to replace string"
 
 replaceWithParser :: CharParser () Char
diff --git a/src/IDE/Statusbar.hs b/src/IDE/Statusbar.hs
--- a/src/IDE/Statusbar.hs
+++ b/src/IDE/Statusbar.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Statusbar
@@ -45,7 +46,9 @@
 import Graphics.UI.Frame.Panes (IDEPane(..), paneName)
 import Text.Printf (printf)
 import Control.Monad.IO.Class (MonadIO(..))
-
+import Data.Text (Text)
+import qualified Data.Text as T (pack, lines, unpack)
+import Data.Monoid ((<>))
 
 changeStatusbar :: [StatusbarCompartment] -> IDEAction
 changeStatusbar = postAsyncIDE . mapM_ changeStatusbar'
@@ -63,10 +66,10 @@
     changeStatusbar' (CompartmentPane Nothing) =  do
         sb <- getSBActivePane
         liftIO $ statusbarPop sb 1
-        liftIO $ statusbarPush sb 1 ""
+        liftIO $ statusbarPush sb 1 ("" :: Text)
         return ()
     changeStatusbar' (CompartmentState string) =  do
-        let realStr = if '\n' `elem` string then head (lines string) ++ " ..." else string
+        let realStr = if '\n' `elem` T.unpack string then head (T.lines string) <> " ..." else string
         sb <- getSBErrors
         liftIO $ statusbarPop sb 1
         liftIO $ statusbarPush sb 1 realStr
@@ -76,17 +79,17 @@
         window <- getMainWindow
         liftIO $ statusbarPop sb 1
         liftIO $ statusbarPush sb 1 string
-        liftIO $ set window [ windowTitle := "Leksah: " ++  string ]
+        liftIO $ set window [ windowTitle := "Leksah: " <> string ]
         return ()
     changeStatusbar' (CompartmentBufferPos (line,col)) =  do
         sb <- getStatusbarLC
         liftIO $ statusbarPop sb 1
-        liftIO $ statusbarPush sb 1 $ printf "Ln %4d, Col %3d" (line + 1) (col + 1)
+        liftIO $ statusbarPush sb 1 (T.pack $ printf "Ln %4d, Col %3d" (line + 1) (col + 1))
         return ()
     changeStatusbar' (CompartmentOverlay modi) =  do
         sb <- getStatusbarIO
         liftIO $ statusbarPop sb 1
-        liftIO $ statusbarPush sb 1 $ if modi then "OVR" else "INS"
+        liftIO $ statusbarPush sb 1 $ if modi then "OVR" else ("INS" :: Text)
         return ()
     changeStatusbar' (CompartmentBuild bool) =  do
         im <- getImBuild
@@ -101,39 +104,39 @@
 buildStatusbar :: IO HBox
 buildStatusbar = do
     sblk <- statusbarNew
-    widgetSetName sblk "statusBarSpecialKeys"
+    widgetSetName sblk ("statusBarSpecialKeys" :: Text)
     widgetSetSizeRequest sblk 150 (-1)
 
     sbap <- statusbarNew
-    widgetSetName sbap "statusBarActivePane"
+    widgetSetName sbap ("statusBarActivePane" :: Text)
     widgetSetSizeRequest sbap 150 (-1)
 
     sbapr <- statusbarNew
-    widgetSetName sbapr "statusBarActiveProject"
+    widgetSetName sbapr ("statusBarActiveProject" :: Text)
     widgetSetSizeRequest sbapr 150 (-1)
 
     sbe <- statusbarNew
-    widgetSetName sbe "statusBarErrors"
+    widgetSetName sbe ("statusBarErrors" :: Text)
     widgetSetSizeRequest sbe 150 (-1)
 
     sblc <- statusbarNew
-    widgetSetName sblc "statusBarLineColumn"
+    widgetSetName sblc ("statusBarLineColumn" :: Text)
     widgetSetSizeRequest sblc 150 (-1)
 
     sbio <- statusbarNew
-    widgetSetName sbio "statusBarInsertOverwrite"
+    widgetSetName sbio ("statusBarInsertOverwrite" :: Text)
     widgetSetSizeRequest sbio 60 (-1)
 
     buildImage <- imageNewFromStock "ide_empty" IconSizeMenu
-    widgetSetName buildImage "buildImage"
+    widgetSetName buildImage ("buildImage" :: Text)
     imageSetPixelSize buildImage 16
 
     collectImage <- imageNewFromStock "ide_empty" IconSizeMenu
-    widgetSetName collectImage "collectImage"
+    widgetSetName collectImage ("collectImage" :: Text)
     imageSetPixelSize collectImage 16
 
     hb <- hBoxNew False 1
-    widgetSetName hb "statusBox"
+    widgetSetName hb ("statusBox" :: Text)
     boxPackStart hb sblk PackGrow 0
     boxPackStart hb sbap PackGrow 0
     boxPackStart hb sbapr PackGrow 0
diff --git a/src/IDE/SymbolNavigation.hs b/src/IDE/SymbolNavigation.hs
--- a/src/IDE/SymbolNavigation.hs
+++ b/src/IDE/SymbolNavigation.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.SymbolNavigation
@@ -47,6 +48,8 @@
 import Control.Monad.Reader.Class (MonadReader(..))
 import IDE.Core.State (reflectIDE)
 import Control.Applicative ((<$>))
+import Data.Text (Text)
+import qualified Data.Text as T (length)
 
 data Locality = LocalityPackage  | LocalityWorkspace | LocalitySystem  -- in which category symbol is located
     deriving (Ord,Eq,Show)
@@ -57,7 +60,7 @@
     => EditorView editor -- ^ source buffer view
     -> ScrolledWindow    -- ^ container window
     -> (Bool -> Bool -> EditorIter editor -> IDEM (EditorIter editor, EditorIter editor)) -- ^ identifiermapper (bools=control,shift)
-    -> (Bool -> Bool -> String -> IDEM ()) -- ^ click handler
+    -> (Bool -> Bool -> Text -> IDEM ()) -- ^ click handler
     -> IDEM [Connection]
 createHyperLinkSupport sv sw identifierMapper clickHandler = do
     tv <- getEditorWidget sv
@@ -91,7 +94,7 @@
             removeTagByName tvb "link"
             offs <- getLineOffset beg
             offsc <- getLineOffset iter
-            if (length slice > 1) then do
+            if (T.length slice > 1) then do
                 if (click) then do
                         liftIO $ pointerUngrab eventTime
                         clickHandler ctrlPressed shiftPressed slice
diff --git a/src/IDE/TextEditor/Class.hs b/src/IDE/TextEditor/Class.hs
--- a/src/IDE/TextEditor/Class.hs
+++ b/src/IDE/TextEditor/Class.hs
@@ -28,6 +28,7 @@
 import Control.Monad.Reader.Class (MonadReader(..))
 import Control.Monad.IO.Class (MonadIO(..))
 import System.Glib.Signals (on)
+import Data.Text (Text)
 
 class TextEditor editor where
     data EditorBuffer editor
@@ -37,9 +38,9 @@
     data EditorTagTable editor
     data EditorTag editor
 
-    newBuffer :: Maybe FilePath -> String -> IDEM (EditorBuffer editor)
+    newBuffer :: Maybe FilePath -> Text -> IDEM (EditorBuffer editor)
     applyTagByName :: EditorBuffer editor
-                      -> String
+                      -> Text
                       -> EditorIter editor
                       -> EditorIter editor
                       -> IDEM ()
@@ -71,17 +72,17 @@
                 -> EditorIter editor
                 -> EditorIter editor
                 -> Bool
-                -> IDEM String
+                -> IDEM Text
     getStartIter :: EditorBuffer editor -> IDEM (EditorIter editor)
     getTagTable :: EditorBuffer editor -> IDEM (EditorTagTable editor)
     getText :: EditorBuffer editor
                -> EditorIter editor
                -> EditorIter editor
                -> Bool
-               -> IDEM String
+               -> IDEM Text
     hasSelection :: EditorBuffer editor -> IDEM Bool
-    insert :: EditorBuffer editor -> EditorIter editor -> String -> IDEM ()
-    newView :: EditorBuffer editor -> Maybe String -> IDEM (EditorView editor)
+    insert :: EditorBuffer editor -> EditorIter editor -> Text -> IDEM ()
+    newView :: EditorBuffer editor -> Maybe Text -> IDEM (EditorView editor)
     pasteClipboard :: EditorBuffer editor
                       -> Clipboard
                       -> EditorIter editor
@@ -90,12 +91,12 @@
     placeCursor :: EditorBuffer editor -> EditorIter editor -> IDEM ()
     redo :: EditorBuffer editor -> IDEM ()
     removeTagByName :: EditorBuffer editor
-                       -> String
+                       -> Text
                        -> IDEM ()
     selectRange :: EditorBuffer editor -> EditorIter editor -> EditorIter editor -> IDEM ()
     setModified :: EditorBuffer editor -> Bool -> IDEM ()
-    setStyle :: Bool -> EditorBuffer editor -> Maybe String -> IDEM ()
-    setText :: EditorBuffer editor -> String -> IDEM ()
+    setStyle :: Bool -> EditorBuffer editor -> Maybe Text -> IDEM ()
+    setText :: EditorBuffer editor -> Text -> IDEM ()
     undo :: EditorBuffer editor -> IDEM ()
 
     -- Events
@@ -122,7 +123,7 @@
                     -> Double
                     -> Maybe (Double, Double)
                     -> IDEM ()
-    setFont :: EditorView editor -> Maybe String -> IDEM ()
+    setFont :: EditorView editor -> Maybe Text -> IDEM ()
     setIndentWidth :: EditorView editor -> Int -> IDEM ()
     setWrapMode :: EditorView editor -> Bool -> IDEM ()
     setRightMargin :: EditorView editor -> Maybe Int -> IDEM ()
@@ -172,7 +173,7 @@
                        -> Maybe (EditorIter editor)
                        -> IDEM (Maybe (EditorIter editor))
     forwardSearch :: EditorIter editor
-                     -> String
+                     -> Text
                      -> [TextSearchFlags]
                      -> Maybe (EditorIter editor)
                      -> IDEM (Maybe (EditorIter editor, EditorIter editor))
@@ -195,8 +196,8 @@
     atStart :: EditorIter editor -> IDEM (EditorIter editor)
 
     -- Tag Table
-    newTag :: EditorTagTable editor -> String -> IDEM (EditorTag editor)
-    lookupTag :: EditorTagTable editor -> String -> IDEM (Maybe (EditorTag editor))
+    newTag :: EditorTagTable editor -> Text -> IDEM (EditorTag editor)
+    lookupTag :: EditorTagTable editor -> Text -> IDEM (Maybe (EditorTag editor))
 
     -- Tag
     background :: EditorTag editor -> Color -> IDEM ()
diff --git a/src/IDE/TextEditor/CodeMirror.hs b/src/IDE/TextEditor/CodeMirror.hs
--- a/src/IDE/TextEditor/CodeMirror.hs
+++ b/src/IDE/TextEditor/CodeMirror.hs
@@ -1,8 +1,10 @@
+{-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE NoImplicitPrelude #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.TextEditor.CodeMirror
@@ -35,6 +37,21 @@
 import Data.Typeable (Typeable)
 import Graphics.UI.Gtk (scrolledWindowSetShadowType)
 import Graphics.UI.Gtk.General.Enums (ShadowType(..))
+import Data.Text (Text)
+import Text.Show (Show)
+import Data.Tuple (snd, fst)
+import Data.Function (($), (.))
+import Data.Maybe (Maybe, Maybe(..))
+import GHC.Base (Functor(..), Monad(..))
+import Data.Int (Int)
+import System.IO (FilePath)
+import Data.List ((++))
+import Data.Bool (Bool(..), not)
+import GHC.Real (fromIntegral, RealFrac(..))
+import GHC.Num (Num(..))
+import Data.Eq (Eq(..))
+import GHC.Float (Double)
+import qualified Data.Text as T (pack)
 
 #ifdef LEKSAH_WITH_CODE_MIRROR
 import Control.Monad (unless)
@@ -60,7 +77,7 @@
 import System.Glib.Signals (after, on)
 import Graphics.UI.Gtk.WebKit.JavaScriptCore.WebFrame
        (webFrameGetGlobalContext)
-import Text.Blaze.Html.Renderer.String (renderHtml)
+import Text.Blaze.Html.Renderer.Text (renderHtml)
 import Text.Hamlet (shamlet)
 import Graphics.UI.Gtk
        (ScrolledWindow, menuPopup, menuAttachToWidget, menuNew,
@@ -120,9 +137,12 @@
             Nothing    -> do
                 mainIteration
                 loop mvar
+
 type CodeMirrorRef = (WebView, MVar CodeMirrorState)
 
-body                  = js  "body"
+
+
+body              = js  "body"
 value             = js  "value"
 setSize           = js2 "setSize"
 mode              = js  "mode"
@@ -177,7 +197,7 @@
         i ^. ch   <# (fromIntegral c :: Double)
         return $ CMIter cm i
 
-newCMBuffer :: Maybe FilePath -> String -> IDEM (EditorBuffer CodeMirror)
+newCMBuffer :: Maybe FilePath -> Text -> IDEM (EditorBuffer CodeMirror)
 newCMBuffer mbFilename contents = do
     ideR <- ask
     liftIO $ do
@@ -205,7 +225,7 @@
                 liftIO $ debugM "leksah" "newCMBuffer loaded"
                 liftIO . putMVar s $ CodeMirrorState{..}
 
-        webViewLoadString cmWebView (
+        webViewLoadString cmWebView (T.pack $
                    "<html><head>"
                 ++ "<script src=\"lib/codemirror.js\">"
                 ++ "<link rel=\"stylesheet\" href=\"lib/codemirror.css\">"
@@ -214,7 +234,7 @@
                 ++ "</head>"
                 ++ "<body style=\"margin:0;padding:0 auto;\">"
                 ++ "</body></html>"
-            ) Nothing Nothing ("file://" ++ dataDir ++ "/codemirror.html")
+            ) Nothing (T.pack $ "file://" ++ dataDir ++ "/codemirror.html")
         debugM "leksah" "newCMBuffer loading"
         return $ CMBuffer (cmWebView, s)
 
@@ -302,12 +322,12 @@
         lift $ CMIter cm <$> (m ^. getCursor "head" >>= valToObject)
     getSlice (CMBuffer cm) (CMIter _ first) (CMIter _ last) includeHidenChars = runCM cm $ do
         m <- codeMirror
-        lift $ unpack <$> (m ^. getRange first last >>= valToText)
+        lift $ m ^. getRange first last >>= valToText
     getStartIter (CMBuffer cm) = runCM cm $ cmIter cm 0 0
     getTagTable (CMBuffer cm) = return $ CMTagTable cm
     getText (CMBuffer cm) (CMIter _ first) (CMIter _ last) includeHidenChars = runCM cm $ do
         m <- codeMirror
-        lift $ unpack <$> (m ^. getRange first last >>= valToText)
+        lift $ m ^. getRange first last >>= valToText
     hasSelection (CMBuffer cm) = runCM cm $ do
         m <- codeMirror
         lift $ (m ^. somethingSelected) >>= valToBool
diff --git a/src/IDE/TextEditor/GtkSourceView.hs b/src/IDE/TextEditor/GtkSourceView.hs
--- a/src/IDE/TextEditor/GtkSourceView.hs
+++ b/src/IDE/TextEditor/GtkSourceView.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.TextEditor.GtkSourceView
@@ -117,6 +118,9 @@
 import System.Glib.Attributes (get, AttrOp(..), set)
 import qualified Graphics.UI.Gtk as Gtk (endUserAction)
 import IDE.Utils.GUIUtils (fontDescription)
+import Data.Text (Text)
+import qualified Data.Text as T (all, length, pack)
+import Data.Monoid ((<>))
 
 transformGtkIter :: EditorIter GtkSourceView -> (TextIter -> IO a) -> IDEM (EditorIter GtkSourceView)
 transformGtkIter (GtkIter i) f = do
@@ -134,7 +138,7 @@
 
 data GtkSourceView = GtkSourceView deriving( Typeable, Show )
 
-newGtkBuffer :: Maybe FilePath -> String -> IDEM (EditorBuffer GtkSourceView)
+newGtkBuffer :: Maybe FilePath -> Text -> IDEM (EditorBuffer GtkSourceView)
 newGtkBuffer mbFilename contents = liftIO $ do
     lm      <- sourceLanguageManagerNew
     dataDir <- getDataDir
@@ -142,14 +146,14 @@
     sourceLanguageManagerSetSearchPath lm (Just $ (dataDir </> "language-specs") : oldPath)
     mbLang  <- case mbFilename of
         Just filename -> do
-            guess <- contentTypeGuess filename contents (length contents)
+            guess <- contentTypeGuess filename contents (T.length contents)
             sourceLanguageManagerGuessLanguage lm (Just filename) $
                 case guess of
                     (True, _)  -> Just "text/x-haskell"
                     (False, t) -> Just t
-        Nothing -> sourceLanguageManagerGuessLanguage lm Nothing (Just "text/x-haskell")
+        Nothing -> sourceLanguageManagerGuessLanguage lm Nothing (Just ("text/x-haskell" :: Text))
     mbLang2 <- case mbLang of
-                    Nothing -> sourceLanguageManagerGuessLanguage lm Nothing (Just "text/x-haskell")
+                    Nothing -> sourceLanguageManagerGuessLanguage lm Nothing (Just ("text/x-haskell" :: Text))
                     _ -> return mbLang
     buffer <- case mbLang2 of
         Just sLang -> sourceBufferNewWithLanguage sLang
@@ -241,7 +245,7 @@
                 dataDir <- getDataDir
                 sourceStyleSchemeManagerAppendSearchPath styleManager $ dataDir </> "data/styles"
                 ids <- sourceStyleSchemeManagerGetSchemeIds styleManager
-                let preferedNames = if preferDark then [str++"-dark", str] else [str]
+                let preferedNames = if preferDark then [str<>"-dark", str] else [str]
                 forM_ (take 1 $ filter (flip elem ids) preferedNames) $ \ name -> do
                     scheme <- sourceStyleSchemeManagerGetScheme styleManager name
                     sourceBufferSetStyleScheme sb (Just scheme)
@@ -335,7 +339,7 @@
                         let isIdent a = isAlphaNum a || a == '\'' || a == '_' || a == '.'
                         let isOp    a = isSymbol   a || a == ':'  || a == '\\' || a == '*' || a == '/' || a == '-'
                                                      || a == '!'  || a == '@' || a == '%' || a == '&' || a == '?'
-                        if (all isIdent text) || (all isOp text)
+                        if (T.all isIdent text) || (T.all isOp text)
                             then do
                                 hasSel <- textBufferHasSelection sb
                                 if not hasSel
@@ -441,10 +445,10 @@
     lookupTag (GtkTagTable tt) name = liftIO $ fmap GtkTag <$> textTagTableLookup tt name
 
     -- Tag
-    background (GtkTag t) color = liftIO $ set t [textTagBackground := colorHexString color]
+    background (GtkTag t) color = liftIO $ set t [textTagBackground := T.pack $ colorHexString color]
     underline (GtkTag t) value = liftIO $ set t [textTagUnderline := value]
 
-simpleGtkBuffer :: String -> IDEM (EditorBuffer GtkSourceView)
+simpleGtkBuffer :: Text -> IDEM (EditorBuffer GtkSourceView)
 simpleGtkBuffer contents = liftIO $ GtkBuffer <$> do
     buffer <- sourceBufferNew Nothing
     textBufferSetText buffer contents
diff --git a/src/IDE/TextEditor/Yi.hs b/src/IDE/TextEditor/Yi.hs
--- a/src/IDE/TextEditor/Yi.hs
+++ b/src/IDE/TextEditor/Yi.hs
@@ -33,6 +33,8 @@
 
 import Data.Typeable (Typeable)
 import Graphics.UI.Gtk (castToWidget)
+import Data.Text (Text)
+import qualified Data.Text as T (pack, unpack)
 
 #ifdef LEKSAH_WITH_YI
 import IDE.TextEditor.Class (TextEditor(..))
@@ -48,9 +50,9 @@
         readCharB, nextWordB, moveToEol, rightB, rightN, nextPointB,
         unitWord, atBoundaryB, moveToSol, prevWordB, leftB, readB,
         doUntilB_, prevPointB, Mode, modifyMode, insertingA, undoB,
-        markSavedB, setSelectRegionB, redoB, setMarkPointB, insertNAt,
+        markSavedB, setSelectRegionB, redoB, markPointA, insertNAt,
         regionIsEmpty, regionEnd, regionStart, selMark, isUnchangedBuffer,
-        Point(..), MarkValue(..), lineOf, getMarkPointB, pointOfLineColB,
+        Point(..), MarkValue(..), lineOf, pointOfLineColB,
         askMarks, insMark, sizeB, getRawestSelectRegionB, mkRegion,
         deleteRegionB, newMarkB, Mark, pointB, moveTo, savingPointB, Point,
         withGivenBuffer0, liftEditor, BufferM, BufferRef, Mode(..),
@@ -86,13 +88,13 @@
 data Yi = Yi deriving( Typeable, Show )
 
 #ifdef LEKSAH_WITH_YI
-newYiBuffer :: Maybe FilePath -> String -> IDEM (EditorBuffer Yi)
+newYiBuffer :: Maybe FilePath -> Text -> IDEM (EditorBuffer Yi)
 newYiBuffer mbFilename contents = do
     liftYiControl $ do
         let (filename, id) = case mbFilename of
                                 Just fn -> (fn, Right fn)
                                 Nothing -> ("Unknown.hs", Left "*leksah*")
-        buffer <- Yi.newBuffer id contents
+        buffer <- Yi.newBuffer id (T.unpack contents)
         setBufferMode filename buffer
         return $ YiBuffer buffer
 
@@ -164,7 +166,7 @@
     getEndIter (YiBuffer b) = iterFromYiBuffer b sizeB
     getInsertMark (YiBuffer b) = YiMark <$> (withYiBuffer b $ insMark <$> askMarks)
     getIterAtLine (YiBuffer b) line = iterFromYiBuffer b $ pointOfLineColB line 1
-    getIterAtMark (YiBuffer b) (YiMark m) = iterFromYiBuffer b $ getMarkPointB m
+    getIterAtMark (YiBuffer b) (YiMark m) = iterFromYiBuffer b $ (use . markPointA) m
     getIterAtOffset (YiBuffer b) offset = return $ mkYiIter b $ Point offset
     getLineCount (YiBuffer b) = withYiBuffer b $ sizeB >>= lineOf
     getModified (YiBuffer b) = not <$> (withYiBuffer b $ gets isUnchangedBuffer)
@@ -175,17 +177,17 @@
                 mkYiIter b (regionEnd region))
     getInsertIter (YiBuffer b) = withYiBuffer b $ do
         insertMark <- insMark <$> askMarks
-        mkYiIter b <$> getMarkPointB insertMark
-    getSlice (YiBuffer b) (YiIter first) (YiIter last) includeHidenChars = liftYiControl $
+        mkYiIter b <$> (use . markPointA) insertMark
+    getSlice (YiBuffer b) (YiIter first) (YiIter last) includeHidenChars = liftYiControl $ T.pack <$>
         Yi.getText b first last
     getStartIter (YiBuffer b) = return $ mkYiIter b $ Point 0
     getTagTable (YiBuffer b) = return YiTagTable -- TODO
-    getText (YiBuffer b) (YiIter first) (YiIter last) includeHidenChars = liftYiControl $
+    getText (YiBuffer b) (YiIter first) (YiIter last) includeHidenChars = liftYiControl $ T.pack <$>
         Yi.getText b first last
     hasSelection (YiBuffer b) = withYiBuffer b $ do
         region <- getRawestSelectRegionB
         return $ not $ regionIsEmpty region
-    insert (YiBuffer b) (YiIter (Iter _ p)) text = withYiBuffer b $ insertNAt text p
+    insert (YiBuffer b) (YiIter (Iter _ p)) text = withYiBuffer b $ insertNAt (T.unpack text) p
     newView (YiBuffer b) mbFontString = do
         fd <- fontDescription mbFontString
         liftYiControl $ fmap YiView $ Yi.newView b fd
@@ -199,7 +201,7 @@
         now <- liftIO $ getCurrentTime
         withYiBuffer b $ markSavedB now
     setStyle preferDark (YiBuffer b) mbStyle = return () -- TODO
-    setText (YiBuffer b) text = liftYiControl $ Yi.setText b text
+    setText (YiBuffer b) text = liftYiControl $ Yi.setText b (T.unpack text)
     undo (YiBuffer b) =  withYiBuffer b undoB
     bufferToWindowCoords (YiView v) point = return point -- TODO
     drawTabs (YiView _) = return () -- TODO
diff --git a/src/IDE/Utils/ExternalTool.hs b/src/IDE/Utils/ExternalTool.hs
--- a/src/IDE/Utils/ExternalTool.hs
+++ b/src/IDE/Utils/ExternalTool.hs
@@ -36,11 +36,13 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import Data.Maybe (isNothing)
 import Control.Applicative ((<$>))
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, pack, null)
 
 runExternalTool' :: MonadIDE m
-                => String
+                => Text
                 -> FilePath
-                -> [String]
+                -> [Text]
                 -> FilePath
                 -> C.Sink ToolOutput IDEM ()
                 -> m ()
@@ -59,9 +61,9 @@
 runExternalTool :: MonadIDE m
                 => m Bool
                 -> (ProcessHandle -> IDEM ())
-                -> String
+                -> Text
                 -> FilePath
-                -> [String]
+                -> [Text]
                 -> FilePath
                 -> C.Sink ToolOutput IDEM ()
                 -> m ()
@@ -70,7 +72,7 @@
         run <- runGuard
         when run $ do
             when (saveAllBeforeBuild prefs) (do fileSaveAll belongsToWorkspace; return ())
-            unless (null description) . void $
+            unless (T.null description) . void $
                 triggerEventIDE (StatusbarChanged [CompartmentState description, CompartmentBuild True])
             reifyIDE $ \ideR -> forkIO $ do
                 -- If vado is enabled then look up the mount point and transform
@@ -79,8 +81,8 @@
                 (executable', args') <- case mountPoint of
                                             Left mp -> do
                                                 s <- readSettings
-                                                a <- vado mp s dir [] executable args
-                                                return ("ssh", a)
+                                                a <- vado mp s dir [] executable (map T.unpack args)
+                                                return ("ssh", map T.pack a)
                                             _ -> return (executable, args)
                 -- Run the tool
                 (output, pid) <- runTool executable' args' (Just dir)
diff --git a/src/IDE/Utils/GUIUtils.hs b/src/IDE/Utils/GUIUtils.hs
--- a/src/IDE/Utils/GUIUtils.hs
+++ b/src/IDE/Utils/GUIUtils.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE CPP, ScopedTypeVariables #-}
+{-# LANGUAGE CPP, ScopedTypeVariables, OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Utils.GUIUtils
@@ -61,6 +61,9 @@
 --    (ResponseId(..))
 import Control.Monad.IO.Class (liftIO)
 import Control.Exception as E
+import Data.Text (Text)
+import Data.Monoid ((<>))
+import qualified Data.Text as T (unpack)
 
 #ifdef LOCALIZATION
 
@@ -69,7 +72,7 @@
 
 #endif
 
-chooseDir :: Window -> String -> Maybe FilePath -> IO (Maybe FilePath)
+chooseDir :: Window -> Text -> Maybe FilePath -> IO (Maybe FilePath)
 chooseDir window prompt mbFolder = do
     dialog <- fileChooserDialogNew
                     (Just $ prompt)
@@ -95,7 +98,7 @@
             return Nothing
         _                   -> return Nothing
 
-chooseFile :: Window -> String -> Maybe FilePath -> IO (Maybe FilePath)
+chooseFile :: Window -> Text -> Maybe FilePath -> IO (Maybe FilePath)
 chooseFile window prompt mbFolder = do
     dialog <- fileChooserDialogNew
                     (Just $ prompt)
@@ -121,7 +124,7 @@
             return Nothing
         _                   -> return Nothing
 
-chooseSaveFile :: Window -> String -> Maybe FilePath -> IO (Maybe FilePath)
+chooseSaveFile :: Window -> Text -> Maybe FilePath -> IO (Maybe FilePath)
 chooseSaveFile window prompt mbFolder = do
     dialog <- fileChooserDialogNew
               (Just $ prompt)
@@ -145,24 +148,24 @@
 
 
 
-openBrowser :: String -> IDEAction
+openBrowser :: Text -> IDEAction
 openBrowser url = do
     prefs' <- readIDE prefs
     liftIO (E.catch (do
-                runProcess (browser prefs') [url] Nothing Nothing Nothing Nothing Nothing
+                runProcess (T.unpack $ browser prefs') [T.unpack url] Nothing Nothing Nothing Nothing Nothing
                 return ())
-            (\ (_ :: SomeException) -> sysMessage Normal ("Can't find browser executable " ++ browser prefs')))
+            (\ (_ :: SomeException) -> sysMessage Normal ("Can't find browser executable " <> browser prefs')))
     return ()
 
 
-showDialog :: String -> MessageType -> IO ()
+showDialog :: Text -> MessageType -> IO ()
 showDialog msg msgType = do
     dialog <- messageDialogNew Nothing [] msgType ButtonsOk msg
     _ <- dialogRun dialog
     widgetDestroy dialog
     return ()
 
-showErrorDialog :: String -> IO ()
+showErrorDialog :: Text -> IO ()
 showErrorDialog msg = showDialog msg MessageError
 
 -- get widget elements (menu & toolbar)
@@ -202,12 +205,12 @@
     ui <- getUIAction "ui/menubar/_Configuration/Forget Session" castToToggleAction
     liftIO $toggleActionGetActive ui
 
-getMenuItem :: String -> IDEM MenuItem
+getMenuItem :: Text -> IDEM MenuItem
 getMenuItem path = do
     uiManager' <- getUiManager
     mbWidget   <- liftIO $ uiManagerGetWidget uiManager' path
     case mbWidget of
-        Nothing     -> throwIDE ("State.hs>>getMenuItem: Can't find ui path " ++ path)
+        Nothing     -> throwIDE ("State.hs>>getMenuItem: Can't find ui path " <> path)
         Just widget -> return (castToMenuItem widget)
 
 getBackgroundBuildToggled :: PaneMonad alpha => alpha  (Bool)
@@ -311,25 +314,25 @@
 #ifdef LOCALIZATION
 
 -- | For i18n using hgettext
-__ :: String -> String
-__ = unsafePerformIO . getText
+__ :: Text -> Text
+__ = T.pack . unsafePerformIO . getText . T.unpack
 
 
 #else
 
 -- | For i18n support. Not included in this build.
-__ :: String -> String
+__ :: Text -> Text
 __ = id
 
 #endif
 
-fontDescription :: Maybe String -> IDEM FontDescription
+fontDescription :: Maybe Text -> IDEM FontDescription
 fontDescription mbFontString = liftIO $ do
     case mbFontString of
         Just str -> do
             fontDescriptionFromString str
         Nothing -> do
             f <- fontDescriptionNew
-            fontDescriptionSetFamily f "Monospace"
+            fontDescriptionSetFamily f ("Monospace" :: Text)
             return f
 
diff --git a/src/IDE/Utils/ServerConnection.hs b/src/IDE/Utils/ServerConnection.hs
--- a/src/IDE/Utils/ServerConnection.hs
+++ b/src/IDE/Utils/ServerConnection.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Utils.ServerConnection
@@ -31,6 +32,8 @@
 import Control.Monad.IO.Class (MonadIO(..))
 import System.Log.Logger (getLevel, getRootLogger)
 import Control.Monad (void)
+import qualified Data.Text as T (pack, unpack)
+import Data.Monoid ((<>))
 
 doServerCommand :: ServerCommand -> (ServerAnswer -> IDEM alpha) -> IDEAction
 doServerCommand command cont = do
@@ -46,10 +49,10 @@
         Nothing -> do
             prefs' <- readIDE prefs
             handle <- reifyIDE $ \ideR ->
-                catch (connectTo (serverIP prefs') (PortNumber(PortNum (fromIntegral $ serverPort prefs'))))
+                catch (connectTo (T.unpack $ serverIP prefs') (PortNumber(PortNum (fromIntegral $ serverPort prefs'))))
                     (\(exc :: SomeException) -> do
                         catch (startServer (serverPort prefs'))
-                            (\(exc :: SomeException) -> throwIDE ("Can't start leksah-server" ++ show exc))
+                            (\(exc :: SomeException) -> throwIDE ("Can't start leksah-server" <> T.pack (show exc)))
                         mbHandle <- waitForServer prefs' 100
                         case mbHandle of
                             Just handle ->  return handle
@@ -86,7 +89,7 @@
 waitForServer prefs s = do
     threadDelay 100000 -- 0.1 second
     catch (do
-        handle <- liftIO $ connectTo (serverIP prefs) (PortNumber(PortNum (fromIntegral $ serverPort prefs)))
+        handle <- liftIO $ connectTo (T.unpack $ serverIP prefs) (PortNumber(PortNum (fromIntegral $ serverPort prefs)))
         return (Just handle))
         (\(exc :: SomeException) -> waitForServer prefs (s-1))
 
diff --git a/src/IDE/Workspaces.hs b/src/IDE/Workspaces.hs
--- a/src/IDE/Workspaces.hs
+++ b/src/IDE/Workspaces.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE CPP, ScopedTypeVariables #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Workspace
@@ -88,12 +89,20 @@
 import qualified VCSWrapper.Common as VCS
 import qualified VCSGui.Common as VCSGUI
 import qualified IDE.Workspaces.Writer as Writer
-import Text.Printf (printf)
 import System.Log.Logger (debugM)
 import IDE.Pane.Log (showDefaultLogLaunch', getLog)
 import IDE.LogRef (logOutputDefault)
 import Data.Foldable (forM_)
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, pack)
+import Data.Monoid ((<>))
+import qualified Text.Printf as S (printf)
+import Text.Printf (PrintfType)
+import qualified Data.Text.IO as T (writeFile)
 
+printf :: PrintfType r => Text -> r
+printf = S.printf . T.unpack
+
 -- | Constructs a new workspace and makes it the current workspace
 workspaceNew :: IDEAction
 workspaceNew = do
@@ -110,7 +119,7 @@
         dir <- liftIO $ myCanonicalizePath $ dropFileName realPath
         let cPath = dir </> takeFileName realPath
             newWorkspace = emptyWorkspace {
-                            wsName = takeBaseName cPath,
+                            wsName = T.pack $ takeBaseName cPath,
                             wsFile = cPath}
         liftIO $ writeFields cPath newWorkspace Writer.workspaceDescr
         workspaceOpenThis False (Just cPath)
@@ -142,12 +151,12 @@
                 defaultExists <- doesFileExist defaultWorkspace
                 md <- messageDialogNew (Just mainWindow) [DialogModal] MessageQuestion ButtonsCancel (
                         __ "You need to have a workspace open for this to work. "
-                     ++ __ "Choose ~/leksah.lkshw to "
-                     ++ __ (if defaultExists then "open workspace " else "create a workspace ")
-                     ++ defaultWorkspace)
+                     <> __ "Choose ~/leksah.lkshw to "
+                     <> __ (if defaultExists then "open workspace " else "create a workspace ")
+                     <> T.pack defaultWorkspace)
                 dialogAddButton md (__ "_New Workspace") (ResponseUser 1)
                 dialogAddButton md (__ "_Open Workspace") (ResponseUser 2)
-                dialogAddButton md "~/leksah.lkshw" (ResponseUser 3)
+                dialogAddButton md ("~/leksah.lkshw" :: Text) (ResponseUser 3)
                 dialogSetDefaultResponse md (ResponseUser 3)
                 set md [ windowWindowPosition := WinPosCenterOnParent ]
                 resp <- dialogRun md
@@ -206,7 +215,7 @@
                         Writer.setWorkspace (Just workspace {wsFile = filePath})
                         VCSWS.onWorkspaceOpen workspace)
                            (\ (e :: Exc.SomeException) -> reflectIDE
-                                (ideMessage Normal (printf (__ "Can't load workspace file %s\n%s") filePath (show e))) ideR)
+                                (ideMessage Normal (T.pack $ printf (__ "Can't load workspace file %s\n%s") filePath (show e))) ideR)
 
 
 -- | Closes a workspace
@@ -264,7 +273,7 @@
                         alreadyExists <- liftIO $ doesFileExist (path </> target)
                         unless alreadyExists $ do
                             template <- liftIO $ getModuleTemplate "main" pd "Main" "" ""
-                            liftIO $ UTF8.writeFile (path </> target) template
+                            liftIO $ T.writeFile (path </> target) template
                             fileOpenThis (path </> target)
                     _ -> return ()
             Nothing     -> ideMessage Normal (__ "No package description")
@@ -335,7 +344,7 @@
         Writer.writeWorkspace ws {wsPackages =  delete pack (wsPackages ws)}
     return ()
 
-workspaceActivatePackage :: IDEPackage -> Maybe String -> WorkspaceAction
+workspaceActivatePackage :: IDEPackage -> Maybe Text -> WorkspaceAction
 workspaceActivatePackage pack exe = do
     ws <- ask
     let activePath = takeDirectory $ ipdCabalFile pack
@@ -465,7 +474,7 @@
                     else makePackages settings modifiedPacks (MoComposed steps)
                                         (MoComposed (MoConfigure:steps)) MoMetaInfo
     )
-    (\(e :: Exc.SomeException) -> sysMessage Normal (show e))
+    (\(e :: Exc.SomeException) -> sysMessage Normal (T.pack $ show e))
 
 makePackage ::  PackageAction
 makePackage = do
diff --git a/src/IDE/Workspaces/Writer.hs b/src/IDE/Workspaces/Writer.hs
--- a/src/IDE/Workspaces/Writer.hs
+++ b/src/IDE/Workspaces/Writer.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  IDE.Workspaces.Writer
@@ -46,11 +47,13 @@
     (Parameter(..), (<<<-), paraName, emptyParams)
 import qualified Text.PrettyPrint as  PP (text)
 import System.Log.Logger (debugM)
+import qualified Data.Text as T (pack)
+import Data.Monoid ((<>))
 
 writeWorkspace :: Workspace -> IDEAction
 writeWorkspace ws = do
     timeNow      <- liftIO getClockTime
-    let newWs    =  ws {wsSaveTime = show timeNow,
+    let newWs    =  ws {wsSaveTime = T.pack $ show timeNow,
                          wsVersion = workspaceVersion,
                          wsPackagesFiles = map ipdCabalFile (wsPackages ws)}
     setWorkspace $ Just newWs
@@ -92,13 +95,13 @@
     let wsStr = case mbWs of
                     Nothing -> ""
                     Just ws -> wsName ws
-    let txt = wsStr ++ " "
-                 ++ (case mbPack of
+    let txt = wsStr <> " "
+                 <> (case mbPack of
                             Nothing  -> ""
                             Just p   -> packageIdentifierToString (ipdPackageId p))
-                 ++ (case mbExe of
+                 <> (case mbExe of
                             Nothing  -> ""
-                            Just exe -> " " ++ exe)
+                            Just exe -> " " <> exe)
     triggerEventIDE (StatusbarChanged [CompartmentPackage txt])
     triggerEventIDE (WorkspaceChanged True True)
     triggerEventIDE UpdateWorkspaceInfo
diff --git a/src/IDE/YiConfig.hs b/src/IDE/YiConfig.hs
--- a/src/IDE/YiConfig.hs
+++ b/src/IDE/YiConfig.hs
@@ -22,8 +22,12 @@
 import Data.List (reverse, isPrefixOf)
 
 import Yi
-import Yi.Keymap.Vim
+import qualified Yi.Keymap.Vim as V2
+import qualified Yi.Keymap.Vim.Common as V2
+import qualified Yi.Keymap.Vim.Utils as V2
 
+import qualified Yi.Mode.Haskell as Haskell
+
 import qualified Yi.UI.Pango
 import Yi.UI.Pango.Control
 
@@ -49,94 +53,67 @@
     | modeName m == "haskell" = m { modeGetAnnotations = modeGetAnnotations emptyMode }
     | otherwise = m
 
-defaultYiConfig = defaultConfig
-    {
-        -- Use VTY as the default UI.
-        startFrontEnd = Yi.UI.Pango.start,
-        defaultKm = mkKeymap extendedVimKeymap,
-        modeTable = fmap (onMode $ noHaskellAnnots . prefIndent) (modeTable defaultConfig),
-        configUI = configUI defaultConfig
-    }
+defaultYiConfig = defaultVimConfig {
+    modeTable = myModes ++ modeTable defaultVimConfig,
+    defaultKm = myKeymapSet,
+    configCheckExternalChangesObsessively = False
+}
 
-extendedVimKeymap = defKeymap `override` \super self -> super
-    {
-        v_top_level =
-            (deprioritize >> v_top_level super)
-            -- On 'o' in normal mode I always want to use the indent of the previous line.
-            -- TODO: If the line where the newline is to be inserted is inside a
-            -- block comment then the block comment should be "continued"
-            -- TODO: Ends up I'm trying to replicate vim's "autoindent" feature. This
-            -- should be made a function in Yi.
-            <|> (char 'o' ?>> beginIns self $ do
-                    moveToEol
-                    insertB '\n'
-                    indentAsPreviousB
-                )
-            -- On HLX (Haskell Language Extension) I want to go into insert mode such
-            -- that the cursor position is correctly placed to start entering the name
-            -- of an language extension in a LANGUAGE pragma.
-            -- A language pragma will take either the form
-            -- {-# LANGUAGE Foo #-}
-            -- or
-            -- >{-# LANGUAGE Foo #-}
-            -- The form should be chosen based on the current mode.
-            <|> ( pString "HXL" >> startExtesnionNameInsert self ),
-        v_ins_char =
-            (deprioritize >> v_ins_char super)
-            -- On enter I always want to use the indent of previous line
-            -- TODO: If the line where the newline is to be inserted is inside a
-            -- block comment then the block comment should be "continued"
-            -- TODO: Ends up I'm trying to replicate vim's "autoindent" feature. This
-            -- should be made a function in Yi.
-            <|> ( spec KEnter ?>>! do
-                    insertB '\n'
-                    indentAsPreviousB
-                )
-            -- I want softtabs to be deleted as if they are tabs. So if the
-            -- current col is a multiple of 4 and the previous 4 characters
-            -- are spaces then delete all 4 characters.
-            -- TODO: Incorporate into Yi itself.
-            <|> ( spec KBS ?>>! do
-                    c <- curCol
-                    line <- readRegionB =<< regionOfPartB Line Backward
-                    sw <- indentSettingsB >>= return . shiftWidth
-                    let indentStr = replicate sw ' '
-                        toDel = if (c `mod` sw) /= 0
-                                    then 1
-                                    else if indentStr `isPrefixOf` reverse line
-                                        then sw
-                                        else 1
-                    adjBlock (-toDel)
-                    replicateM_ toDel $ deleteB Character Backward
-                )
-            -- On starting to write a block comment I want the close comment
-            -- text inserted automatically.
-            <|> choice
-                [ pString open_tag >>! do
-                    insertN $ open_tag ++ " \n"
-                    indentAsPreviousB
-                    insertN $ " " ++ close_tag
-                    lineUp
-                 | (open_tag, close_tag) <-
-                    [ ("{-", "-}") -- Haskell block comments
-                    , ("/*", "*/") -- C++ block comments
-                    ]
-                ]
-    }
+defaultSearchKeymap :: Keymap
+defaultSearchKeymap = do
+    Event (KASCII c) [] <- anyEvent
+    write (isearchAddE [c])
 
+myKeymapSet :: KeymapSet
+myKeymapSet = V2.mkKeymapSet $ V2.defVimConfig `override` \super this ->
+    let eval = V2.pureEval this
+    in super {
+          -- Here we can add custom bindings.
+          -- See Yi.Keymap.Vim.Common for datatypes and
+          -- Yi.Keymap.Vim.Utils for useful functions like mkStringBindingE
 
-startExtesnionNameInsert :: ModeMap -> I Event Action ()
-startExtesnionNameInsert self = beginIns self $ do
-    p_current <- pointB
-    m_current <- getMarkB (Just "'")
-    setMarkPointB m_current p_current
-    moveTo $ Point 0
-    insertB '\n'
-    moveTo $ Point 0
-    insertN "{-# LANGUAGE "
-    p <- pointB
-    insertN " #-}"
-    moveTo p
+          -- In case of conflict, that is if there exist multiple bindings
+          -- whose prereq function returns WholeMatch,
+          -- the first such binding is used.
+          -- So it's important to have custom bindings first.
+          V2.vimBindings = myBindings eval ++ V2.vimBindings super
+        }
+
+myBindings :: (String -> EditorM ()) -> [V2.VimBinding]
+myBindings eval =
+    let nmap x y = V2.mkStringBindingE V2.Normal V2.Drop (x, y, id)
+        imap x y = V2.VimBindingE (\evs state -> case V2.vsMode state of
+                                    V2.Insert _ ->
+                                        fmap (const (y >> return V2.Continue))
+                                             (evs `V2.matchesString` x)
+                                    _ -> V2.NoMatch)
+    in [
+         -- Tab traversal
+         nmap "<C-h>" previousTabE
+       , nmap "<C-l>" nextTabE
+       , nmap "<C-l>" nextTabE
+
+         -- Press space to clear incremental search highlight
+       , nmap " " (eval ":nohlsearch<CR>")
+
+         -- for times when you don't press shift hard enough
+       , nmap ";" (eval ":")
+
+       , nmap "<F3>" (withBuffer0 deleteTrailingSpaceB)
+       , nmap "<F4>" (withBuffer0 moveToSol)
+       , nmap "<F1>" (withBuffer0 readCurrentWordB >>= printMsg)
+
+       , imap "<Home>" (withBuffer0 moveToSol)
+       , imap "<End>" (withBuffer0 moveToEol)
+       ]
+
+myModes = [
+         AnyMode Haskell.fastMode {
+             -- Disable beautification
+             modePrettify = const $ return ()
+           , modeGetAnnotations = (const . const) []
+         }
+    ]
 
 #else
 
diff --git a/tests/IDE/TextEditor/Tests.hs b/tests/IDE/TextEditor/Tests.hs
--- a/tests/IDE/TextEditor/Tests.hs
+++ b/tests/IDE/TextEditor/Tests.hs
@@ -131,7 +131,7 @@
 
 allEditors :: (forall editor. TextEditor editor
            => (   Maybe FilePath
-                    -> String
+                    -> Text
                     -> IDEM (EditorBuffer editor))
                -> IDEM Bool)
            -> IO Bool
@@ -147,9 +147,9 @@
         hFlush stdout
         hFlush stderr
         debugM "leksah" $ show editor
-        testIDE $ test (newBuffer :: Maybe FilePath -> String -> IDEM (EditorBuffer editor))
+        testIDE $ test (newBuffer :: Maybe FilePath -> Text -> IDEM (EditorBuffer editor))
 
-prop_test :: String -> Property
+prop_test :: Text -> Property
 prop_test s = monadicIO $ do
     let input = filter (not . flip elem "\NUL\r") s
     result <- run $ allEditors (\buf -> do
diff --git a/win32/makeinstaller.sh b/win32/makeinstaller.sh
--- a/win32/makeinstaller.sh
+++ b/win32/makeinstaller.sh
@@ -3,7 +3,7 @@
 . scripts/stage.sh || exit
 
 export CABAL_USER_BIN=$HOME/AppData/Roaming/cabal/bin
-export GHC_USER_PREFIX=$HOME/AppData/Roaming/cabal/i386-windows-ghc-`ghc$GHCVERSION --numeric-version`
+export GHC_USER_PREFIX=$HOME/AppData/Roaming/cabal/x86_64-windows-ghc-`ghc$GHCVERSION --numeric-version`
 export LEKSAH_PREFIX=$GHC_USER_PREFIX
 export LEKSAH_SERVER_PREFIX=$GHC_USER_PREFIX
 export HLINT_X_X_X_X=`ghc-pkg$GHCVERSION list |grep '^ *hlint-' | tail -n1 | tr -d ' \n'`
@@ -41,76 +41,76 @@
 cp -ru "$LEKSAH_PREFIX/$GHCJS_CODEMIRROR_X_X_X_X"/keymap SourceDir/ghcjs-codemirror
 cp -ru "$LEKSAH_PREFIX/$GHCJS_CODEMIRROR_X_X_X_X"/theme SourceDir/ghcjs-codemirror
 mkdir -p SourceDir/bin
-cp -u  "$CABAL_USER_BIN"/leksah.exe SourceDir/bin
-cp -u  "$CABAL_USER_BIN"/vcswrapper.exe SourceDir/bin
-cp -u  "$CABAL_USER_BIN"/vcsgui.exe SourceDir/bin
-cp -u  "$CABAL_USER_BIN"/vcsgui-askpass.exe SourceDir/bin
-cp -u  "$CABAL_USER_BIN"/leksah-server.exe SourceDir/bin
-cp -u  "$CABAL_USER_BIN"/leksahecho.exe SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/iconv.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/icudata50.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/icui18n50.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/icule50.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/icuuc50.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libatk-1.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libbz2-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libcairo-2.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libcairo-gobject-2.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libcrypto-10.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libcurl-4.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libenchant.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libexpat-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libffi-6.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libfontconfig-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libfreetype-6.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgailutil-3-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgcc_s_sjlj-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgdk-3-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgdk_pixbuf-2.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgio-2.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libglib-2.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgmodule-2.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgobject-2.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgst*-1.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgthread-2.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgtk-3-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libgtksourceview-3.0-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libharfbuzz-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libharfbuzz-icu-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libidn-11.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libintl-8.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libjavascriptcoregtk-3.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libjpeg-62.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libpango-1.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libpangocairo-1.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libpangoft2-1.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libpangowin32-1.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libpixman-1-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libpng16-16.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libsoup-2.4-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libsqlite3-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libssh2-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libssl-10.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libstdc++-6.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libxml2-2.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libxslt-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libwebkitgtk-3.0-0.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libwebp-4.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/libwinpthread-1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/zlib1.dll SourceDir/bin
-cp -u  "$GTK_PREFIX"/bin/pkg-config.exe SourceDir/bin
+cp -u  "$CABAL_USER_BIN"/leksah.exe SourceDir/bin
+cp -u  "$CABAL_USER_BIN"/vcswrapper.exe SourceDir/bin
+cp -u  "$CABAL_USER_BIN"/vcsgui.exe SourceDir/bin
+cp -u  "$CABAL_USER_BIN"/vcsgui-askpass.exe SourceDir/bin
+cp -u  "$CABAL_USER_BIN"/leksah-server.exe SourceDir/bin
+cp -u  "$CABAL_USER_BIN"/leksahecho.exe SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/iconv.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/icudata50.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/icui18n50.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/icule50.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/icuuc50.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libatk-1.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libbz2-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libcairo-2.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libcairo-gobject-2.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libcrypto-10.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libcurl-4.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libenchant.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libexpat-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libffi-6.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libfontconfig-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libfreetype-6.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgailutil-3-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgcc_s_sjlj-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgdk-3-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgdk_pixbuf-2.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgio-2.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libglib-2.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgmodule-2.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgobject-2.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgst*-1.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgthread-2.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgtk-3-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libgtksourceview-3.0-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libharfbuzz-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libharfbuzz-icu-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libidn-11.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libintl-8.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libjavascriptcoregtk-3.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libjpeg-62.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libpango-1.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libpangocairo-1.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libpangoft2-1.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libpangowin32-1.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libpixman-1-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libpng16-16.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libsoup-2.4-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libsqlite3-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libssh2-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libssl-10.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libstdc++-6.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libxml2-2.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libxslt-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libwebkitgtk-3.0-0.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libwebp-4.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/libwinpthread-1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/zlib1.dll SourceDir/bin
+cp -u  "$GTK_PREFIX"/bin/pkg-config.exe SourceDir/bin
 mkdir -p SourceDir/share
-cp -ru "$GTK_PREFIX"/share/themes SourceDir/share
-cp -ru "$GTK_PREFIX"/share/glib-2.0 SourceDir/share
-cp -ru "$GTK_PREFIX"/share/gtksourceview-3.0 SourceDir/share
+cp -ru "$GTK_PREFIX"/share/themes SourceDir/share
+cp -ru "$GTK_PREFIX"/share/glib-2.0 SourceDir/share
+cp -ru "$GTK_PREFIX"/share/gtksourceview-3.0 SourceDir/share
 mkdir -p SourceDir/libexec
-cp -ru "$GTK_PREFIX"/libexec/gstreamer-1.0 SourceDir/libexec
+cp -ru "$GTK_PREFIX"/libexec/gstreamer-1.0 SourceDir/libexec
 
-cp -ru "$GTK_PREFIX"/include SourceDir
-cp -ru "$GTK_PREFIX"/lib SourceDir
+cp -ru "$GTK_PREFIX"/include SourceDir
+cp -ru "$GTK_PREFIX"/lib SourceDir
 
 # mkdir -p SourceDir/fonts
-# cp -ru /c/Windows/Fonts/DejaVuS*.ttf SourceDir
+# cp -ru /c/Windows/Fonts/DejaVuS*.ttf SourceDir
 
 heat dir SourceDir -srd -gg -sfrag -template fragment -out heat.wxs -cg Leksah -dr INSTALLDIR -sreg suppress registry harvesting || exit
 candle heat.wxs || exit