diff --git a/src/VCSGui/Common/Commit.hs b/src/VCSGui/Common/Commit.hs
--- a/src/VCSGui/Common/Commit.hs
+++ b/src/VCSGui/Common/Commit.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  Main
@@ -30,6 +31,8 @@
 import Control.Monad.Reader
 import Data.Maybe
 import Paths_vcsgui(getDataFileName)
+import qualified Data.Text as T (unpack, pack)
+import Data.Text (Text)
 
 --
 -- glade path and object accessors
@@ -47,7 +50,7 @@
 --
 
 -- | This function will be called after the ok action is called.
-type OkCallBack = String    -- ^ Commit message as specified in the GUI.
+type OkCallBack = Text    -- ^ Commit message as specified in the GUI.
             -> [FilePath]   -- ^ List of 'FilePath's of the files that were selected.
             -> [Option]     -- ^ options (this is currently not implemented i.e. '[]' is passed)
             -> Wrapper.Ctx ()
@@ -66,8 +69,8 @@
 }
 
 -- | Represents a file which can be selected for commiting.
-data SCFile = GITSCFile Bool FilePath String |
-              SVNSCFile Bool FilePath String Bool
+data SCFile = GITSCFile Bool FilePath Text |
+              SVNSCFile Bool FilePath Text Bool
     deriving (Show)
 
 -- | Return 'True' if the 'SCFile' is flagged as selected.
@@ -81,7 +84,7 @@
 filePath (SVNSCFile _ fp _ _) = fp
 
 -- | Return the status of this file.
-status :: SCFile -> String
+status :: SCFile -> Text
 status (GITSCFile _ _ s) = s
 status (SVNSCFile _ _ s _) = s
 
@@ -92,7 +95,7 @@
 
 
 -- | Options to the 'OkCallBack'.
-type Option = String
+type Option = Text
 
 
 -- | Display a window to enter a commit message and select files to be commited.
@@ -150,7 +153,7 @@
             return (selectedFiles)
 
 getTreeViewFromGladeCustomStore :: Builder
-                        -> String
+                        -> Text
                         -> TreeViewSetter
                         -> Wrapper.Ctx (H.TreeViewItem SCFile)
 getTreeViewFromGladeCustomStore builder name setupListStore = do
@@ -166,9 +169,9 @@
 wrapWidget :: GObjectClass objClass =>
      Builder
      -> (GObject -> objClass)
-     -> String -> IO (String, objClass)
+     -> Text -> IO (Text, objClass)
 wrapWidget builder cast name = do
-    putStrLn $ " cast " ++ name
+    putStrLn $ " cast " ++ T.unpack name
     gobj <- builderGetObject builder cast name
     return (name, gobj)
 
diff --git a/src/VCSGui/Common/ConflictsResolved.hs b/src/VCSGui/Common/ConflictsResolved.hs
--- a/src/VCSGui/Common/ConflictsResolved.hs
+++ b/src/VCSGui/Common/ConflictsResolved.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.ConflictsResolved
diff --git a/src/VCSGui/Common/Error.hs b/src/VCSGui/Common/Error.hs
--- a/src/VCSGui/Common/Error.hs
+++ b/src/VCSGui/Common/Error.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.Error
@@ -15,11 +16,12 @@
 module VCSGui.Common.Error (
     showErrorGUI
 ) where
-import Graphics.UI.Gtk
 
+import Graphics.UI.Gtk
+import Data.Text (Text)
 
 -- | Displays a simple window displaying given 'String' as an error message.
-showErrorGUI :: String -- ^ Message to display.
+showErrorGUI :: Text -- ^ Message to display.
     -> IO ()
 showErrorGUI msg = do
     dialog <- messageDialogNew Nothing [] MessageError ButtonsOk msg
diff --git a/src/VCSGui/Common/ExceptionHandler.hs b/src/VCSGui/Common/ExceptionHandler.hs
--- a/src/VCSGui/Common/ExceptionHandler.hs
+++ b/src/VCSGui/Common/ExceptionHandler.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.ExceptionHandler
@@ -20,6 +21,8 @@
 
 import VCSWrapper.Common
 import VCSGui.Common.Error
+import qualified Data.Text as T (unwords, unlines)
+import Data.Monoid ((<>))
 
 
 -- | Wraps an IO computation to display an error message if a 'VCSException' occurs.
@@ -30,7 +33,7 @@
     case o of
         Left (VCSException exitCode out err repoLocation (cmd:opts)) -> do
             putStrLn $ "exception caught"
-            showErrorGUI $ unlines ["An error occured.", err, "Details:", "command: " ++ cmd, "options: " ++ unwords opts]
+            showErrorGUI $ T.unlines ["An error occured.", err, "Details:", "command: " <> cmd, "options: " <> T.unwords opts]
         Right _ -> do
             putStrLn $ "no exception"
             return ()
diff --git a/src/VCSGui/Common/FilesInConflict.hs b/src/VCSGui/Common/FilesInConflict.hs
--- a/src/VCSGui/Common/FilesInConflict.hs
+++ b/src/VCSGui/Common/FilesInConflict.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.FilesInConflict
@@ -28,6 +30,8 @@
 import Control.Monad
 import Control.Monad.Reader
 import Paths_vcsgui(getDataFileName)
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, pack)
 
 --
 -- glade path and object accessors
@@ -93,7 +97,7 @@
     gui <- loadGUI $ setUpTreeView cwd filesInConflict filesToResolveGetter resolveMarker eMergeToolSetter
     mbMergeToolSetter <- case eMergeToolSetter of
                             Left (Merge.MergeTool path) -> do
-                                liftIO $ H.set (entPath gui) path
+                                liftIO $ H.set (entPath gui) $ T.pack path
                                 return Nothing
                             Right setter -> return $ Just setter
 
@@ -111,7 +115,7 @@
                 Nothing -> return ()
                 Just path -> do
                     -- update gui
-                    H.set (entPath gui) path
+                    H.set (entPath gui) $ T.pack path
                     -- call setter
                     case mbMergeToolSetter of
                         Nothing -> return ()
@@ -154,7 +158,7 @@
         H.addColumnToTreeView' treeViewItem
                                renderer
                                "File"
-                               $ \scf -> [cellText := filePath scf]
+                               $ \scf -> [cellText := T.pack $ filePath scf]
 
         renderer <- cellRendererToggleNew
         H.addColumnToTreeView' treeViewItem
@@ -163,7 +167,7 @@
                                $ \scf -> [cellToggleActive := isResolved scf]
 
         -- connect select action
-        on renderer cellToggled $ \columnId -> do
+        on renderer cellToggled $ \(columnId :: Text) -> do
                                 putStrLn $ "Checkbutton clicked at column " ++ (show columnId)
                                 --TODO only call tool if button is not checked, move this code to being called if a click on row is received
                                 let callTool' = (\path -> Wrapper.runVcs config $ callTool columnId listStore path)
@@ -181,7 +185,7 @@
                         Just treeIter <- liftIO $ treeModelGetIterFromString listStore columnId
                         value <- liftIO $ listStoreGetValue listStore $ listStoreIterToIndex treeIter
                         filesToResolve <- filesToResolveGetter $ filePath value
-                        resolvedByTool <- liftIO $ Process.exec mbcwd pathToTool filesToResolve
+                        resolvedByTool <- liftIO $ Process.exec mbcwd pathToTool $ map T.pack filesToResolve
                         let setResolved' = setResolved listStore treeIter value
                         case resolvedByTool of
                                     False -> ConflictsResolvedGUI.showConflictsResolvedGUI
@@ -203,7 +207,7 @@
 ----
 
 getTreeViewFromGladeCustomStore :: Builder
-                        -> String
+                        -> Text
                         -> (TreeView -> Wrapper.Ctx (ListStore SCFile)) -- ^ fn defining how to setup the liststore
                         -> Wrapper.Ctx (H.TreeViewItem SCFile)
 getTreeViewFromGladeCustomStore builder name setupListStore = do
@@ -219,9 +223,9 @@
 wrapWidget :: GObjectClass objClass =>
      Builder
      -> (GObject -> objClass)
-     -> String -> IO (String, objClass)
+     -> Text -> IO (Text, objClass)
 wrapWidget builder cast name = do
-    putStrLn $ " cast " ++ name
+    putStrLn $ " cast " ++ T.unpack name
     gobj <- builderGetObject builder cast name
     return (name, gobj)
 
@@ -244,7 +248,7 @@
 -- HELPER
 
 -- | shows a dialog to choose a folder, returns Just FilePath to folder if succesfull, Nothing if cancelled
-showFolderChooserDialog :: String -- ^ title of the window
+showFolderChooserDialog :: Text -- ^ title of the window
     -> Window -- ^ parent window
     -> FileChooserAction
     -> IO (Maybe FilePath)
diff --git a/src/VCSGui/Common/GtkHelper.hs b/src/VCSGui/Common/GtkHelper.hs
--- a/src/VCSGui/Common/GtkHelper.hs
+++ b/src/VCSGui/Common/GtkHelper.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.GtkHelper
@@ -65,35 +66,37 @@
 import System.Directory
 import Control.Monad.Trans(liftIO)
 import System.IO (hPutStrLn, stderr)
-import VCSGui.Common.Helpers (emptyListToNothing)
+import VCSGui.Common.Helpers (emptyTextToNothing)
+import Data.Text (Text)
+import qualified Data.Text as T (unpack)
 
 -- Typesynonyms
-type WindowItem = (String, Gtk.Window, ())
-type ActionItem = (String, Gtk.Action, ())
-type LabelItem = (String, Gtk.Label, (IO (Maybe String), String -> IO ()))
-type TextEntryItem = (String, Gtk.Entry, (IO (Maybe String), String -> IO ()))
-type ComboBoxItem = (String, Gtk.ComboBox, (IO (Maybe String), [String] -> IO ()))
-type TextViewItem = (String, Gtk.TextView, (IO (Maybe String), String -> IO ()))
-type TreeViewItem a = (String, (Gtk.ListStore a, Gtk.TreeView), (IO (Maybe [a]), [a] -> IO ()))
-type CheckButtonItem = (String, Gtk.CheckButton, (IO Bool, Bool -> IO()))
-type ButtonItem = (String, Gtk.Button, (IO String, String -> IO()))
+type WindowItem = (Text, Gtk.Window, ())
+type ActionItem = (Text, Gtk.Action, ())
+type LabelItem = (Text, Gtk.Label, (IO (Maybe Text), Text -> IO ()))
+type TextEntryItem = (Text, Gtk.Entry, (IO (Maybe Text), Text -> IO ()))
+type ComboBoxItem = (Text, Gtk.ComboBox, (IO (Maybe Text), [Text] -> IO ()))
+type TextViewItem = (Text, Gtk.TextView, (IO (Maybe Text), Text -> IO ()))
+type TreeViewItem a = (Text, (Gtk.ListStore a, Gtk.TreeView), (IO (Maybe [a]), [a] -> IO ()))
+type CheckButtonItem = (Text, Gtk.CheckButton, (IO Bool, Bool -> IO()))
+type ButtonItem = (Text, Gtk.Button, (IO Text, Text -> IO()))
 
 -- Type accessors
 
 -- | return the name of this item (as in the gladefile)
-getName :: (String, a, b) -> String
+getName :: (Text, a, b) -> Text
 getName (n, _, _) = n
 
 -- | return the Gtk object wrapped by given item
-getItem :: (String, a, b) -> a
+getItem :: (Text, a, b) -> a
 getItem (_, item, _) = item
 
 -- | call teh get method of an *Item
-get :: (String, a, (b, c)) -> b
+get :: (Text, a, (b, c)) -> b
 get (_, _, (getter, _)) = getter
 
 -- | call the set method of an *Item
-set :: (String, a, (b, c)) -> c
+set :: (Text, a, (b, c)) -> c
 set (_,_, (_, setter)) = setter
 
 
@@ -111,7 +114,7 @@
 
 -- | Get a 'WindowItem' from a gladefile.
 getWindowFromGlade :: Gtk.Builder
-    -> String -- ^ name of the window to get as specified in the gladefile.
+    -> Text -- ^ name of the window to get as specified in the gladefile.
     -> IO WindowItem
 getWindowFromGlade builder name = do
     (a, b) <- wrapWidget builder Gtk.castToWindow name
@@ -119,7 +122,7 @@
 
 -- | Get an 'ActionItem' from a gladefile.
 getActionFromGlade :: Gtk.Builder
-    -> String -- ^ name of the action to get as specified in the gladefile.
+    -> Text -- ^ name of the action to get as specified in the gladefile.
     -> IO ActionItem
 getActionFromGlade builder name = do
     (a, b) <- wrapWidget builder Gtk.castToAction name
@@ -127,42 +130,42 @@
 
 -- | Get an 'LabelItem' from a gladefile.
 getLabelFromGlade :: Gtk.Builder
-    -> String -- ^ name of the label to get as specified in the gladefile.
+    -> Text -- ^ name of the label to get as specified in the gladefile.
     -> IO LabelItem
 getLabelFromGlade builder name = do
     (_, entry) <- wrapWidget builder Gtk.castToLabel name
-    let getter = error "don't call get on a gtk label!" :: IO (Maybe String)
+    let getter = error "don't call get on a gtk label!" :: IO (Maybe Text)
         setter val = Gtk.labelSetText entry val :: IO ()
     return (name, entry, (getter, setter))
 
 -- | Get a 'ButtonItem' from a gladefile.
 getButtonFromGlade :: Gtk.Builder
-    -> String -- ^ name of the button to get as specified in the gladefile.
+    -> Text -- ^ name of the button to get as specified in the gladefile.
     -> IO ButtonItem
 getButtonFromGlade builder name = do
     (_,btn) <- wrapWidget builder Gtk.castToButton name
-    let getter = Gtk.buttonGetLabel btn :: IO String
+    let getter = Gtk.buttonGetLabel btn :: IO Text
         setter val = Gtk.buttonSetLabel btn val
     return (name, btn, (getter,setter))
 
 -- | Get a 'TextEntryItem' from a gladefile.
 getTextEntryFromGlade :: Gtk.Builder
-    -> String -- ^ name of the text entry to get as specified in the gladefile.
+    -> Text -- ^ name of the text entry to get as specified in the gladefile.
     -> IO TextEntryItem
 getTextEntryFromGlade builder name = do
     (_, entry) <- wrapWidget builder Gtk.castToEntry name
-    let getter = fmap emptyListToNothing $ Gtk.entryGetText entry :: IO (Maybe String)
+    let getter = fmap emptyTextToNothing $ Gtk.entryGetText entry :: IO (Maybe Text)
         setter val = Gtk.entrySetText entry val :: IO ()
     return (name, entry, (getter, setter))
 
 -- | Get a 'ComboBoxItem' from a gladefile.
 getComboBoxFromGlade :: Gtk.Builder
-                    -> String -- ^ name of the combo box to get as specified in the gladefile.
+                    -> Text -- ^ name of the combo box to get as specified in the gladefile.
                     -> IO ComboBoxItem
 getComboBoxFromGlade builder name = do
     (_, combo) <- wrapWidget builder Gtk.castToComboBox name
     Gtk.comboBoxSetModelText combo
-    let getter = Gtk.comboBoxGetActiveText combo  :: IO (Maybe String) -- get selected text
+    let getter = Gtk.comboBoxGetActiveText combo  :: IO (Maybe Text) -- get selected text
         setter entries = do -- fill with new entries
             store <- Gtk.comboBoxGetModelText combo
             Gtk.listStoreClear store
@@ -172,13 +175,13 @@
 
 -- | Get a 'TextViewItem' from a gladefile.
 getTextViewFromGlade :: Gtk.Builder
-    -> String -- ^ name of the text view to get as specified in the gladefile.
+    -> Text -- ^ name of the text view to get as specified in the gladefile.
     -> IO TextViewItem
 getTextViewFromGlade builder name =  do
         (_, entry)  <- wrapWidget builder Gtk.castToTextView name
         buffer <- Gtk.textViewGetBuffer entry
-        let getter = getLongText buffer :: IO (Maybe String)
-            setter = (\text -> Gtk.textBufferSetText buffer text) :: String -> IO ()
+        let getter = getLongText buffer :: IO (Maybe Text)
+            setter = (\text -> Gtk.textBufferSetText buffer text) :: Text -> IO ()
         return (name, entry, (getter, setter))
     where
     getLongText buffer = do
@@ -191,7 +194,7 @@
 
 -- | Get a 'CheckButtonItem' from a gladefile.
 getCheckButtonFromGlade :: Gtk.Builder
-    -> String -- ^ name of the check button to get as specified in the gladefile.
+    -> Text -- ^ name of the check button to get as specified in the gladefile.
     -> IO CheckButtonItem
 getCheckButtonFromGlade builder name = do
         (_,bt) <- wrapWidget builder Gtk.castToCheckButton name
@@ -205,7 +208,7 @@
 
 -- | Get a 'TreeViewItem' from a gladefile.
 getTreeViewFromGlade :: Gtk.Builder
-    -> String -- ^ name of the tree view to get as specified in the gladefile.
+    -> Text -- ^ name of the tree view to get as specified in the gladefile.
     -> [a] -- ^ Content of the new tree view.
     -> IO (TreeViewItem a)
 getTreeViewFromGlade builder name rows = do
@@ -217,7 +220,7 @@
 
 -- | Get a 'TreeViewItem' from a gladefile.
 getTreeViewFromGladeCustomStore :: Gtk.Builder
-                        -> String -- ^ name of the tree view to get as specified in the gladefile.
+                        -> Text -- ^ name of the tree view to get as specified in the gladefile.
                         -> (Gtk.TreeView -> IO (Gtk.ListStore a)) -- ^ fn defining how to setup the liststore
                         -> IO (TreeViewItem a)
 getTreeViewFromGladeCustomStore builder name setupListStore = do
@@ -291,7 +294,7 @@
 addColumnToTreeView :: Gtk.CellRendererClass r =>
     TreeViewItem a
     -> r -- ^ CellRenderer
-    -> String -- ^ title
+    -> Text -- ^ title
     -> (a -> [Gtk.AttrOp r]) -- ^ mapping
     -> IO ()
 addColumnToTreeView (_, item, _) = do
@@ -306,7 +309,7 @@
 addColumnToTreeView' :: Gtk.CellRendererClass r =>
     (Gtk.ListStore a, Gtk.TreeView)
     -> r
-    -> String
+    -> Text
     -> (a -> [Gtk.AttrOp r])
     -> IO ()
 addColumnToTreeView' (listStore, listView) renderer title value2attributes = do
@@ -318,7 +321,7 @@
 
 -- | Shortcut for adding text columns to a TreeView. See 'addColumnToTreeView'.
 addTextColumnToTreeView :: TreeViewItem a
-    -> String -- ^ title
+    -> Text -- ^ title
     -> (a -> [Gtk.AttrOp Gtk.CellRendererText]) -- ^ mapping
     -> IO ()
 addTextColumnToTreeView tree title map = do
@@ -327,7 +330,7 @@
 
 -- | Shortcut for adding text columns to a TreeView. See 'addColumnToTreeView\''.
 addTextColumnToTreeView' :: (Gtk.ListStore a, Gtk.TreeView)
-    -> String
+    -> Text
     -> (a -> [Gtk.AttrOp Gtk.CellRendererText])
     -> IO ()
 addTextColumnToTreeView' item title map = do
@@ -341,8 +344,8 @@
 wrapWidget :: Gtk.GObjectClass objClass =>
      Gtk.Builder
      -> (Gtk.GObject -> objClass)
-     -> String -> IO (String, objClass)
+     -> Text -> IO (Text, objClass)
 wrapWidget builder cast name = do
-    hPutStrLn stderr $ " cast " ++ name
+    hPutStrLn stderr $ " cast " ++ T.unpack name
     gobj <- Gtk.builderGetObject builder cast name
     return (name, gobj)
diff --git a/src/VCSGui/Common/Helpers.hs b/src/VCSGui/Common/Helpers.hs
--- a/src/VCSGui/Common/Helpers.hs
+++ b/src/VCSGui/Common/Helpers.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.Helpers
@@ -14,9 +15,16 @@
 
 module VCSGui.Common.Helpers (
     emptyListToNothing
+  , emptyTextToNothing
 ) where
 
+import Data.Text (Text)
+
 -- | Return 'Nothing' if given list is empty, 'Just' the list otherwise.
 emptyListToNothing :: [a] -> Maybe [a]
 emptyListToNothing [] = Nothing
 emptyListToNothing l = Just l
+
+emptyTextToNothing :: Text -> Maybe Text
+emptyTextToNothing "" = Nothing
+emptyTextToNothing l = Just l
diff --git a/src/VCSGui/Common/Log.hs b/src/VCSGui/Common/Log.hs
--- a/src/VCSGui/Common/Log.hs
+++ b/src/VCSGui/Common/Log.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.Log
@@ -11,7 +13,6 @@
 -- | Functions to show a log window. This mostly hides the window-building tasks from the specific VCS implementation.
 --
 -----------------------------------------------------------------------------
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 module VCSGui.Common.Log (
     showLogGUI
 ) where
@@ -26,11 +27,14 @@
 
 import Data.Maybe (fromMaybe)
 import Paths_vcsgui(getDataFileName)
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
+import Data.Monoid ((<>))
 
 getGladepath = getDataFileName "data/guiCommonLog.glade"
 
 data LogConfig a = LogConfig {
-    options :: [String]
+    options :: [Text]
     ,treeViewSetter :: Gtk.TreeView -> TreeViewItem a
 }
 
@@ -52,14 +56,14 @@
 -- | Show the history of a repository.
 showLogGUI :: [Common.LogEntry]
             -- ^ logEntries to be displayed initially
-            -> [String]
+            -> [Text]
             -- ^ options will be displayed in a menu as checkboxes (TODO this is currently not implemented)
-            -> Maybe ((String, [String]), (String -> Common.Ctx [Common.LogEntry]))
+            -> Maybe ((Text, [Text]), (Text -> Common.Ctx [Common.LogEntry]))
             -- ^ (list of branchnames to display, Function called when a different branch is selected)
             --
             -- The function will be called with the selected branchname to repopulate the displayed LogEntries.
             -- If 'Nothing', no branch selection will be displayed.
-            -> (Common.LogEntry -> Maybe String -> Common.Ctx ())
+            -> (Common.LogEntry -> Maybe Text -> Common.Ctx ())
             -- ^ (selected line, name of the branch to checkout from)
             --
             -- This function is called on checkout action. The window will be closed afterwards.
@@ -72,9 +76,9 @@
         return ()
 
 guiWithoutBranches :: [Common.LogEntry]
-                    -> [String]
+                    -> [Text]
                     -> (Common.LogEntry
-                        -> (Maybe String)
+                        -> (Maybe Text)
                         -> Common.Ctx ())
                     -> Bool -- ^ Add column to display branch name
                     -> Common.Ctx LogGUI
@@ -107,14 +111,14 @@
     setupLogColumns gui displayBranchNames = do
         let item = (logTreeView gui)
         addTextColumnToTreeView item "Subject" (\Common.LogEntry { Common.subject = t } -> [Gtk.cellText Gtk.:= t])
-        addTextColumnToTreeView item "Author" (\Common.LogEntry { Common.author = t, Common.email = mail } -> [Gtk.cellText Gtk.:= (t ++ " <" ++ mail ++ ">")])
+        addTextColumnToTreeView item "Author" (\Common.LogEntry { Common.author = t, Common.email = mail } -> [Gtk.cellText Gtk.:= t <> " <" <> mail <> ">"])
         addTextColumnToTreeView item "Date" (\Common.LogEntry { Common.date = t } -> [Gtk.cellText Gtk.:= t])
         case displayBranchNames of
-            True -> addTextColumnToTreeView item "Branch" (\Common.LogEntry { Common.mbBranch = t } -> [Gtk.cellText Gtk.:= (fromMaybe "" t)])
+            True -> addTextColumnToTreeView item "Branch" (\Common.LogEntry { Common.mbBranch = t } -> [Gtk.cellText Gtk.:= fromMaybe "" t])
             False -> return()
         return ()
 
-guiAddBranches :: LogGUI -> (String, [String]) -> (String -> Common.Ctx [Common.LogEntry]) -> Common.Ctx ()
+guiAddBranches :: LogGUI -> (Text, [Text]) -> (Text -> Common.Ctx [Common.LogEntry]) -> Common.Ctx ()
 guiAddBranches gui (curBranch, otherBranches) changeBranchFn = do
         -- set branch selection visible
         liftIO $ Gtk.set (getItem $ lblBranch gui) [Gtk.widgetVisible Gtk.:= True]
@@ -130,7 +134,7 @@
         liftIO $ Gtk.on (getItem $ comboBranch gui) Gtk.changed $ changeBranchFn' config (fmap (fromMaybe "") $ get $ comboBranch gui)
         return ()
     where
-    changeBranchFn' :: Common.Config -> IO String -> IO ()
+    changeBranchFn' :: Common.Config -> IO Text -> IO ()
     changeBranchFn' cfg branchIO = do
         let (store, view) = getItem $ logTreeView gui
         branch <- branchIO
diff --git a/src/VCSGui/Common/Process.hs b/src/VCSGui/Common/Process.hs
--- a/src/VCSGui/Common/Process.hs
+++ b/src/VCSGui/Common/Process.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.Process
@@ -22,11 +23,13 @@
 import Control.Concurrent
 import Control.Monad.Reader
 import qualified Control.Exception as Exc
+import Data.Text (Text)
+import qualified Data.Text as T (pack, unpack)
 
 -- | Internal function to execute a vcs command
 exec :: Maybe FilePath -- ^ working directory or Nothing if not set
-     -> String -- ^ mergetool command, e.g. kdiff3.sh
-     -> [String] -- ^ files, last one is output
+     -> Text -- ^ mergetool command, e.g. kdiff3.sh
+     -> [Text] -- ^ files, last one is output
      -> IO Bool
 exec mcwd cmd opts = do
     (ec, out, err) <- readProc mcwd cmd opts
@@ -36,12 +39,12 @@
 
 -- | same as readProcessWithExitCode but having a configurable cwd and env,
 readProc :: Maybe FilePath --working directory or Nothing if not set
-            -> String  --command
-            -> [String] -- ^ files, last one is output
-            -> IO (ExitCode, String, String)
+            -> Text  --command
+            -> [Text] -- ^ files, last one is output
+            -> IO (ExitCode, Text, Text)
 readProc mcwd cmd files = do
     putStrLn $ "Executing process, mcwd: "++show mcwd++"cmd: "++show cmd++",files: "++show files
-    (_, Just outh, Just errh, pid) <- createProcess (proc cmd files)
+    (_, Just outh, Just errh, pid) <- createProcess (proc (T.unpack cmd) (map T.unpack files))
                                             { std_out = CreatePipe,
                                               std_err = CreatePipe,
                                               cwd = mcwd
@@ -63,6 +66,6 @@
     hClose errh
 
     ex <- waitForProcess pid
-    return (ex, out, err)
+    return (ex, T.pack out, T.pack err)
 
 
diff --git a/src/VCSGui/Common/SetupConfig.hs b/src/VCSGui/Common/SetupConfig.hs
--- a/src/VCSGui/Common/SetupConfig.hs
+++ b/src/VCSGui/Common/SetupConfig.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Common.SetupConfig
@@ -28,6 +29,9 @@
 import qualified VCSGui.Common.GtkHelper as H
 import qualified VCSGui.Common.MergeTool as MergeTool
 import qualified VCSWrapper.Common as Wrapper
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, pack)
+import Control.Applicative ((<$>))
 
 type Config = Maybe (Wrapper.VCSType, Wrapper.Config, Maybe MergeTool.MergeTool)
             --config for setting up vcs
@@ -138,16 +142,16 @@
                 Just path -> do
                     -- discover vcs
                     availableVCS <- discoverVCS path
-                    H.set (comboBoxVCSType gui) $ map (\vcs -> show vcs) availableVCS
+                    H.set (comboBoxVCSType gui) $ map (T.pack . show) availableVCS
                     -- update gui
-                    H.set (entRepo gui) path
+                    H.set (entRepo gui) (T.pack path)
                     return ()
         on (H.getItem (actBrowseExec gui)) actionActivated $ liftIO $ do
             mbExec <- showFolderChooserDialog "Choose executable location" (H.getItem $ winSetupRepo gui) FileChooserActionOpen
             case mbExec of
                 Nothing -> return ()
                 Just exec -> do
-                    H.set (entExec gui) exec
+                    H.set (entExec gui) (T.pack exec)
                     H.set (checkbtExec gui) True
                     return ()
 
@@ -183,12 +187,12 @@
                 Nothing -> return ()
                 Just path -> do
                     -- update gui
-                    H.set (entPathToTool gui) path
+                    H.set (entPathToTool gui) (T.pack path)
                     return ()
         return ()
 
     where
-    createVCSTypAndConfig :: SetupRepoGUI -> IO (Either String (Wrapper.VCSType, Wrapper.Config, Maybe MergeTool.MergeTool))
+    createVCSTypAndConfig :: SetupRepoGUI -> IO (Either Text (Wrapper.VCSType, Wrapper.Config, Maybe MergeTool.MergeTool))
     createVCSTypAndConfig gui = do
             path <- H.get (entRepo gui)
 
@@ -207,7 +211,7 @@
                                 return (Nothing,Nothing)
             selectedVCSType <- H.get (comboBoxVCSType gui)
             mbPathToTool <- H.get (entPathToTool gui)
-            let tuple = createVCSTypAndConfig' path author mail exec selectedVCSType mbPathToTool
+            let tuple = createVCSTypAndConfig' (T.unpack <$> path) author mail (T.unpack <$> exec) (T.unpack <$> selectedVCSType) (T.unpack <$> mbPathToTool)
             putStrLn $ "tuple"++show tuple
             return tuple
             where
@@ -237,9 +241,9 @@
                 case mbPath of
                     Nothing -> return ()
                     Just path -> do
-                                    H.set (entRepo gui) $ path
+                                    H.set (entRepo gui) $ T.pack path
                                     availableVCS <- discoverVCS path
-                                    H.set (comboBoxVCSType gui) $ map (\vcs -> show vcs) availableVCS
+                                    H.set (comboBoxVCSType gui) $ map (T.pack . show) availableVCS
                                     --get position (hopefully always index in liststore = index in list)
                                     case findIndex (== vcsType) availableVCS of
                                         Just index ->
@@ -252,7 +256,7 @@
                                     return ()
                     Just exec -> do
                                     H.set (checkbtExec gui) True
-                                    H.set (entExec gui) $ exec
+                                    H.set (entExec gui) $ T.pack exec
 
                 case mbAuthor of
                     Nothing -> do
@@ -264,7 +268,7 @@
                                     H.set (entEmail gui) $ fromMaybe "" email
                 case mbMergeTool of
                     Nothing -> return()
-                    Just mergeTool -> H.set (entPathToTool gui) (MergeTool.fullPath mergeTool)
+                    Just mergeTool -> H.set (entPathToTool gui) (T.pack $ MergeTool.fullPath mergeTool)
 
                 return ()
 
@@ -296,7 +300,7 @@
                             _      -> Wrapper.SVN --TODO throw error on this, improve this code
 
 -- | shows a dialog to choose a folder, returns Just FilePath to folder if succesfull, Nothing if cancelled
-showFolderChooserDialog :: String -- ^ title of the window
+showFolderChooserDialog :: Text -- ^ title of the window
     -> Window -- ^ parent window
     -> FileChooserAction
     -> IO (Maybe FilePath)
diff --git a/src/VCSGui/Git/Commit.hs b/src/VCSGui/Git/Commit.hs
--- a/src/VCSGui/Git/Commit.hs
+++ b/src/VCSGui/Git/Commit.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Git.Commit
@@ -26,9 +27,11 @@
 
 import qualified VCSWrapper.Git as Git
 import qualified VCSWrapper.Common as Wrapper
+import Data.Text (Text)
+import qualified Data.Text as T (unpack, pack)
 
 
-doCommit :: String -> [FilePath] -> [Commit.Option] -> Wrapper.Ctx ()
+doCommit :: Text -> [FilePath] -> [Commit.Option] -> Wrapper.Ctx ()
 doCommit commitMsg files _ = do
     Git.add files
     (Wrapper.Config _ _ mbAuthor _) <- ask
@@ -49,9 +52,9 @@
 setupListStore :: TreeView -> Wrapper.Ctx (ListStore Commit.SCFile)
 setupListStore view = do
         repoStatus <- Git.status
-        --GITSCFile Bool FilePath String
-        let selectedF = [Commit.GITSCFile True fp (show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod == Wrapper.Modified || mod == Wrapper.Added]
-            notSelectedF = [Commit.GITSCFile False fp (show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod /= Wrapper.Modified && mod /= Wrapper.Added]
+        --GITSCFile Bool FilePath Text
+        let selectedF = [Commit.GITSCFile True fp (T.pack $ show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod == Wrapper.Modified || mod == Wrapper.Added]
+            notSelectedF = [Commit.GITSCFile False fp (T.pack $ show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod /= Wrapper.Modified && mod /= Wrapper.Added]
 
         liftIO $ do
             store <- listStoreNew (selectedF ++ notSelectedF)
@@ -60,12 +63,12 @@
 
             toggleRenderer <- cellRendererToggleNew
             addColumnToTreeView' item toggleRenderer "Commit" (\(Commit.GITSCFile s _ _)-> [cellToggleActive := s])
-            addTextColumnToTreeView' item "File" (\(Commit.GITSCFile _ p _) -> [cellText := p])
+            addTextColumnToTreeView' item "File" (\(Commit.GITSCFile _ p _) -> [cellText := T.pack p])
             addTextColumnToTreeView' item "File status" (\(Commit.GITSCFile _ _ m) -> [cellText := m])
 
             -- register toggle renderer
             on toggleRenderer cellToggled $ \filepath -> do
-                putStrLn ("toggle called: " ++ filepath)
+                putStrLn ("toggle called: " ++ T.unpack filepath)
 
                 Just treeIter <- treeModelGetIterFromString store filepath
                 value <- listStoreGetValue store $ listStoreIterToIndex treeIter
diff --git a/src/VCSGui/Git/Helpers.hs b/src/VCSGui/Git/Helpers.hs
--- a/src/VCSGui/Git/Helpers.hs
+++ b/src/VCSGui/Git/Helpers.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Git.Helpers
@@ -20,6 +21,8 @@
 import Control.Monad.Reader.Class (asks, MonadReader(..))
 import System.Environment (getEnvironment)
 import Control.Monad.Reader (liftIO)
+import Control.Applicative ((<$>))
+import qualified Data.Text as T (pack)
 
 
 {- | Adds a wrapper to the 'Ctx' so git can ask for a password using a GUI window.
@@ -29,7 +32,8 @@
 askPassWrapper :: Ctx () -> Ctx ()
 askPassWrapper fn = do
     cfgEnv <- asks configEnvironment
-    inheritEnv <- liftIO $ getEnvironment
+    inheritEnv <- map packPair <$> liftIO getEnvironment
     -- TODO better solution for DISPLAY? TODO will this work on windows?
     local (\cfg -> cfg {configEnvironment = ("GIT_ASKPASS", "vcsgui-askpass"):("DISPLAY", ":0.0"):inheritEnv ++ cfgEnv}) fn
-
+  where
+    packPair (a, b) = (T.pack a, T.pack b)
diff --git a/src/VCSGui/Git/Log.hs b/src/VCSGui/Git/Log.hs
--- a/src/VCSGui/Git/Log.hs
+++ b/src/VCSGui/Git/Log.hs
@@ -1,4 +1,6 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Git.Log
@@ -22,7 +24,9 @@
 import qualified VCSWrapper.Git as Git
 import Control.Monad.Reader (liftIO)
 import Data.Maybe (fromMaybe)
-import VCSGui.Common.Helpers (emptyListToNothing)
+import VCSGui.Common.Helpers (emptyTextToNothing)
+import qualified Data.Text as T (unpack, pack)
+import Data.Text (Text)
 
 
 {- | Calls 'Common.showLogGUI' using Git. This will display all log entries. The branch to be displayed can be selected.
@@ -42,22 +46,22 @@
                 liftIO $ putStrLn "checking out selected Branch"
                 Git.checkout (Just selBranch) Nothing
             False -> do
-                liftIO $ putStrLn $ "checking out Commit " ++ (Git.commitID log) ++ ", asking for new branchname"
+                liftIO $ putStrLn $ "checking out Commit " ++ (T.unpack $ Git.commitID log) ++ ", asking for new branchname"
                 mbBranchname <- liftIO $ askForNewBranchname
                 Git.checkout (Just $ Git.commitID log) (mbBranchname)
 
-    askForNewBranchname :: IO (Maybe String)
+    askForNewBranchname :: IO (Maybe Text)
     askForNewBranchname = do
         dialog <- Gtk.dialogNew
-        Gtk.dialogAddButton dialog "gtk-ok" Gtk.ResponseOk
-#if MIN_VERSION_gtk(0,13,0) || defined(MIN_VERSION_gtk3)
+        Gtk.dialogAddButton dialog ("gtk-ok"::Text) Gtk.ResponseOk
+#if defined(MIN_VERSION_gtk3)
         upper <- Gtk.dialogGetContentArea dialog
 #else
         upper <- Gtk.dialogGetUpper dialog
 #endif
 
         inputBranch <- Gtk.entryNew
-        lblBranch <- Gtk.labelNew $ Just "Enter a new branchname (empty for anonym branch):"
+        lblBranch <- Gtk.labelNew $ Just ("Enter a new branchname (empty for anonym branch):" :: Text)
         box <- Gtk.hBoxNew False 2
         Gtk.containerAdd (Gtk.castToBox upper) box
         Gtk.containerAdd box lblBranch
@@ -67,7 +71,7 @@
         _ <- Gtk.dialogRun dialog
         branchname <- Gtk.entryGetText inputBranch
         Gtk.widgetDestroy dialog
-        return $ emptyListToNothing branchname
+        return $ emptyTextToNothing branchname
 
 
 
diff --git a/src/VCSGui/Git/Pull.hs b/src/VCSGui/Git/Pull.hs
--- a/src/VCSGui/Git/Pull.hs
+++ b/src/VCSGui/Git/Pull.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Git.Pull
@@ -22,6 +23,7 @@
 import qualified VCSWrapper.Common as Wrapper
 
 import VCSGui.Common.Error
+import Data.Monoid ((<>))
 
 
 -- | Call 'Git.pull'. If the pull fails or a merge conflict is detected an error message is shown.
@@ -30,4 +32,4 @@
     o <- Git.pull
     case o of
         Right ()     -> return ()
-        Left msg    -> liftIO $ showErrorGUI $ "MERGE CONFLICT " ++ msg
+        Left msg    -> liftIO $ showErrorGUI $ "MERGE CONFLICT " <> msg
diff --git a/src/VCSGui/Mercurial/Commit.hs b/src/VCSGui/Mercurial/Commit.hs
--- a/src/VCSGui/Mercurial/Commit.hs
+++ b/src/VCSGui/Mercurial/Commit.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Mercurial.Commit
@@ -26,8 +27,10 @@
 
 import qualified VCSWrapper.Mercurial as Mercurial
 import qualified VCSWrapper.Common as Wrapper
+import Data.Text (Text)
+import qualified Data.Text as T (pack, unpack)
 
-doCommit :: String -> [FilePath] -> [Commit.Option] -> Wrapper.Ctx ()
+doCommit :: Text -> [FilePath] -> [Commit.Option] -> Wrapper.Ctx ()
 doCommit commitMsg files _ = do
     Mercurial.addremove files
     Mercurial.commit files commitMsg []
@@ -44,9 +47,9 @@
 setupListStore :: TreeView -> Wrapper.Ctx (ListStore Commit.SCFile)
 setupListStore view = do
         repoStatus <- Mercurial.status
-        --GITSCFile Bool FilePath String
-        let selectedF = [Commit.GITSCFile True fp (show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod == Wrapper.Modified || mod == Wrapper.Added]
-            notSelectedF = [Commit.GITSCFile False fp (show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod /= Wrapper.Modified && mod /= Wrapper.Added]
+        --GITSCFile Bool FilePath Text
+        let selectedF = [Commit.GITSCFile True fp (T.pack $ show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod == Wrapper.Modified || mod == Wrapper.Added]
+            notSelectedF = [Commit.GITSCFile False fp (T.pack $ show mod) | (Wrapper.GITStatus fp mod) <- repoStatus, mod /= Wrapper.Modified && mod /= Wrapper.Added]
 
         liftIO $ do
             store <- listStoreNew (selectedF ++ notSelectedF)
@@ -55,12 +58,12 @@
 
             toggleRenderer <- cellRendererToggleNew
             addColumnToTreeView' item toggleRenderer "Commit" (\(Commit.GITSCFile s _ _)-> [cellToggleActive := s])
-            addTextColumnToTreeView' item "File" (\(Commit.GITSCFile _ p _) -> [cellText := p])
+            addTextColumnToTreeView' item "File" (\(Commit.GITSCFile _ p _) -> [cellText := T.pack p])
             addTextColumnToTreeView' item "File status" (\(Commit.GITSCFile _ _ m) -> [cellText := m])
 
             -- register toggle renderer
             on toggleRenderer cellToggled $ \filepath -> do
-                putStrLn ("toggle called: " ++ filepath)
+                putStrLn ("toggle called: " ++ T.unpack filepath)
 
                 Just treeIter <- treeModelGetIterFromString store filepath
                 value <- listStoreGetValue store $ listStoreIterToIndex treeIter
diff --git a/src/VCSGui/Svn/AskPassword.hs b/src/VCSGui/Svn/AskPassword.hs
--- a/src/VCSGui/Svn/AskPassword.hs
+++ b/src/VCSGui/Svn/AskPassword.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Svn.AskPassword
@@ -28,6 +29,7 @@
 import Control.Monad.Trans(liftIO)
 import Paths_vcsgui(getDataFileName)
 import Control.Monad.Reader(ask)
+import Data.Text (Text)
 --
 -- glade path and object accessors
 --
@@ -38,7 +40,7 @@
 accessorEntryPw = "entryPw"
 accessorCheckbtUsePw = "checkbtUsePw"
 accessorCheckbtSaveForSession = "checkbtSaveForSession"
-accessorboxUsePwd = "boxUsePwd"
+accessorboxUsePwd = ("boxUsePwd" :: Text)
 
 {- |
     'Handler' is a function used as an argument to the 'showAskpassGUI'. It represents a VCS
@@ -50,7 +52,7 @@
         * Nothing, no password given
         * Just password, password has been provided
 -}
-type Handler = ((Maybe (Bool, Maybe String))
+type Handler = ((Maybe (Bool, Maybe Text))
                 -> Wrapper.Ctx())
 
 data AskpassGUI = AskpassGUI {
diff --git a/src/VCSGui/Svn/Checkout.hs b/src/VCSGui/Svn/Checkout.hs
--- a/src/VCSGui/Svn/Checkout.hs
+++ b/src/VCSGui/Svn/Checkout.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Svn.Checkout
@@ -24,6 +25,8 @@
 import qualified VCSGui.Common.GtkHelper as H
 import Paths_vcsgui(getDataFileName)
 import Data.Maybe
+import qualified Data.Text as T (unpack, pack)
+import Control.Applicative ((<$>))
 --
 -- glade path and object accessors
 --
diff --git a/src/VCSGui/Svn/Commit.hs b/src/VCSGui/Svn/Commit.hs
--- a/src/VCSGui/Svn/Commit.hs
+++ b/src/VCSGui/Svn/Commit.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  Main
@@ -28,12 +30,14 @@
 
 import Graphics.UI.Gtk
 import Control.Monad.Trans(liftIO)
+import Data.Text (Text)
+import qualified Data.Text as T (pack)
 
 {-  |
     Shows a GUI showing status of subversion and possibilites to commit/cancel.
 -}
 showCommitGUI :: Either M.MergeTool M.MergeToolSetter -- ^ 'MergeTool' is used for any possible conflicts. If not present user will be asked to provide 'MergeTool' on conflicts. 'MergeToolSetter' will be called for response.
-                 -> Either Handler (Maybe String) -- ^ Either 'Handler' for password request or password (nothing for no password)
+                 -> Either Handler (Maybe Text) -- ^ Either 'Handler' for password request or password (nothing for no password)
                  -> Svn.Ctx()
 showCommitGUI eMergeToolSetter eitherHandlerOrPw = do
     conflictingFiles <- SvnH.getConflictingFiles
@@ -50,8 +54,8 @@
         commonCommit = C.showCommitGUI setUpTreeView (okCallback eitherHandlerOrPw)
 
 
-okCallback :: Either Handler (Maybe String) -- ^ either callback for password request or password (nothing for no password)
-            -> String               -- ^ commit message
+okCallback :: Either Handler (Maybe Text) -- ^ either callback for password request or password (nothing for no password)
+            -> Text               -- ^ commit message
             -> [FilePath]           -- ^ selected files
             -> [C.Option]           -- ^ TODO options
             -> Svn.Ctx ()
@@ -90,7 +94,7 @@
         listStore <- listStoreNew [
                 (C.SVNSCFile (ctxSelect (Svn.modification status))
                              (Svn.filePath status)
-                             (show (Svn.modification status))
+                             (T.pack . show $ Svn.modification status)
                              (Svn.isLocked status))
                 | status <- repoStatus]
         treeViewSetModel listView listStore
@@ -104,7 +108,7 @@
                                $ \scf -> [cellToggleActive := C.selected scf]
 
         -- connect select action
-        on renderer cellToggled $ \columnId -> do
+        on renderer cellToggled $ \(columnId :: Text) -> do
                                 Just treeIter <- treeModelGetIterFromString listStore columnId
                                 value <- listStoreGetValue listStore $ listStoreIterToIndex treeIter
                                 let newValue = (\(C.SVNSCFile bool fp s l) -> C.SVNSCFile (not bool) fp s l)
@@ -116,7 +120,7 @@
         H.addColumnToTreeView' treeViewItem
                                renderer
                                "Files to commit"
-                               $ \scf -> [cellText := C.filePath scf]
+                               $ \scf -> [cellText := T.pack $ C.filePath scf]
 
         renderer <- cellRendererTextNew
         H.addColumnToTreeView' treeViewItem
diff --git a/src/VCSGui/Svn/Log.hs b/src/VCSGui/Svn/Log.hs
--- a/src/VCSGui/Svn/Log.hs
+++ b/src/VCSGui/Svn/Log.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Svn.Log
@@ -21,17 +22,19 @@
 
 import qualified VCSWrapper.Svn as Svn
 import qualified VCSWrapper.Common as WC
+import Data.Text (Text)
+import qualified Data.Text as T (unpack)
 
 -- | Shows a GUI showing log for current working copy.
-showLogGUI :: Either Handler (Maybe String) -- ^ Either 'Handler' for password request or password (nothing for no password)
+showLogGUI :: Either Handler (Maybe Text) -- ^ Either 'Handler' for password request or password (nothing for no password)
            -> Svn.Ctx ()
 showLogGUI eitherHandlerOrPw = do
         logEntries <- Svn.simpleLog
         C.showLogGUI logEntries [] Nothing (okCallback eitherHandlerOrPw) False
 
-okCallback :: Either Handler (Maybe String) -- ^ either callback for password request or password (nothing for no password)
+okCallback :: Either Handler (Maybe Text) -- ^ either callback for password request or password (nothing for no password)
            -> WC.LogEntry                   -- ^ chosen logentry
-           -> Maybe String                  -- ^ chosen branch name
+           -> Maybe Text                  -- ^ chosen branch name
            -> WC.Ctx()
 okCallback eitherHandlerOrPw logEntry _ = do
     case eitherHandlerOrPw of
@@ -53,6 +56,6 @@
     doRevert logEntry mbPw = do
                             Svn.mergeHeadToRevision (revision logEntry) mbPw []
                             return()
-    revision logEntry = read $ Svn.commitID logEntry :: Integer
+    revision logEntry = read . T.unpack $ Svn.commitID logEntry :: Integer
 
 
diff --git a/src/VCSGui/Svn/Update.hs b/src/VCSGui/Svn/Update.hs
--- a/src/VCSGui/Svn/Update.hs
+++ b/src/VCSGui/Svn/Update.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  VCSGui.Svn.Update
@@ -26,10 +27,11 @@
 import qualified VCSWrapper.Common as Wrapper
 
 import Control.Monad.Trans(liftIO)
+import Data.Text (Text)
 
 -- | Initiates an update for current SVN working copy.
 showUpdateGUI :: Either M.MergeTool M.MergeToolSetter -- ^ 'MergeTool' is used for any possible conflicts. If not present user will be asked to provide 'MergeTool' on conflicts after updating. 'MergeToolSetter' will be called for response.
-          -> Either AskPassword.Handler (Maybe String) -- ^ If a password is provided it will be used, if not a GUI will be shown to ask for password and given @Handler@ will be called.
+          -> Either AskPassword.Handler (Maybe Text) -- ^ If a password is provided it will be used, if not a GUI will be shown to ask for password and given @Handler@ will be called.
           -> Wrapper.Ctx()
 showUpdateGUI eMergeToolSetter (Left handler) = do
                                 AskPassword.showAskpassGUI $ ownHandler eMergeToolSetter handler
diff --git a/src/exe/askpass/Main.hs b/src/exe/askpass/Main.hs
--- a/src/exe/askpass/Main.hs
+++ b/src/exe/askpass/Main.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 -----------------------------------------------------------------------------
 --
 -- Module      :  Main
@@ -22,6 +23,7 @@
 import Data.Maybe (fromMaybe)
 
 import Paths_vcsgui(getDataFileName)
+import qualified Data.Text as T (unpack)
 --
 -- glade path and object accessors
 --
@@ -56,7 +58,7 @@
     H.registerQuitAction $ actCancel gui
     on (H.getItem (actOk gui)) actionActivated $ do
                                         pw <- H.get (entryPw gui)
-                                        putStr $ fromMaybe "" pw
+                                        putStr . T.unpack $ fromMaybe "" pw
                                         mainQuit
     -- present window
     widgetShowAll $ H.getItem $ window gui
diff --git a/vcsgui.cabal b/vcsgui.cabal
--- a/vcsgui.cabal
+++ b/vcsgui.cabal
@@ -1,5 +1,5 @@
 name: vcsgui
-version: 0.0.4
+version: 0.1.0.0
 cabal-version: >= 1.8
 build-type: Simple
 license: GPL
@@ -38,14 +38,15 @@
                filepath >=1.2.0.0 && < 1.4,
                base >=4.0.0.0 && <4.8,
                directory >=1.1.0.0 && <1.3,
-               mtl >=2.0.1.0 && <2.2,
-               vcswrapper ==0.0.4,
-               process >=1.0.1.5 && <1.3
+               mtl >=2.0.1.0 && <2.3,
+               vcswrapper ==0.1.0,
+               process >=1.0.1.5 && <1.3,
+               text -any
     if flag(gtk3)
-      build-depends: gtk3 >=0.12.4 && <0.13
+      build-depends: gtk3 >=0.13.0.0 && <0.14
       cpp-options:   -DMIN_VERSION_gtk=MIN_VERSION_gtk3
     else
-      build-depends: gtk >=0.12.4 && <0.13
+      build-depends: gtk >=0.13.0.0 && <0.14
     exposed-modules: VCSGui.Common VCSGui.Git VCSGui.Svn VCSGui.Mercurial
     exposed: True
     buildable: True
@@ -68,14 +69,15 @@
                filepath >=1.2.0.0 && < 1.4,
                base >=4.0.0.0 && <4.8,
                directory >=1.1.0.0 && <1.3,
-               mtl >=2.0.1.0 && <2.2,
-               vcswrapper ==0.0.4,
-               process >=1.0.1.5 && <1.3
+               mtl >=2.0.1.0 && <2.3,
+               vcswrapper ==0.1.0,
+               process >=1.0.1.5 && <1.3,
+               text -any
     if flag(gtk3)
-      build-depends: gtk3 >=0.12.4 && <0.13
+      build-depends: gtk3 >=0.12.4 && <0.14
       cpp-options:   -DMIN_VERSION_gtk=MIN_VERSION_gtk3
     else
-      build-depends: gtk >=0.12.4 && <0.13
+      build-depends: gtk >=0.12.4 && <0.14
     if os(osx)
         ghc-options: -optl-headerpad_max_install_names
     buildable: True
@@ -97,14 +99,15 @@
                filepath >=1.2.0.0 && < 1.4,
                base >=4.0.0.0 && <4.8,
                directory >=1.1.0.0 && <1.3,
-               mtl >=2.0.1.0 && <2.2,
-               vcswrapper ==0.0.4,
-               process >=1.0.1.5 && <1.3
+               mtl >=2.0.1.0 && <2.3,
+               vcswrapper ==0.1.0,
+               process >=1.0.1.5 && <1.3,
+               text -any
     if flag(gtk3)
-      build-depends: gtk3 >=0.12.4 && <0.13
+      build-depends: gtk3 >=0.12.4 && <0.14
       cpp-options:   -DMIN_VERSION_gtk=MIN_VERSION_gtk3
     else
-      build-depends: gtk >=0.12.4 && <0.13
+      build-depends: gtk >=0.12.4 && <0.14
     if os(osx)
         ghc-options: -optl-headerpad_max_install_names
     buildable: True