diff --git a/GHC/Paths.hs b/GHC/Paths.hs
new file mode 100644
--- /dev/null
+++ b/GHC/Paths.hs
@@ -0,0 +1,13 @@
+{-# LANGUAGE CPP #-}
+
+module GHC.Paths (
+        ghc, ghc_pkg, libdir, docdir
+  ) where
+
+libdir, docdir, ghc, ghc_pkg :: FilePath
+
+libdir  = GHC_PATHS_LIBDIR
+docdir  = GHC_PATHS_DOCDIR
+
+ghc     = GHC_PATHS_GHC
+ghc_pkg = GHC_PATHS_GHC_PKG
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,29 @@
+Copyright 2008, Simon Marlow
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+ 
+- Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation
+and/or other materials provided with the distribution.
+ 
+- Neither name of the author nor the names of its contributors may be
+used to endorse or promote products derived from this software without
+specific prior written permission. 
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND THE CONTRIBUTORS "AS
+IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY
+COURT OF THE UNIVERSITY OF GLASGOW OR THE CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,74 @@
+import Distribution.Simple
+import Distribution.Simple.Setup
+import Distribution.PackageDescription
+import Distribution.Simple.LocalBuildInfo
+import Distribution.InstalledPackageInfo
+import Distribution.Simple.Program
+import Distribution.Simple.PackageIndex as Pkg
+
+import System.Exit
+import System.IO
+import Data.IORef
+import Data.Char
+import Data.List
+import Data.Maybe
+
+main = defaultMainWithHooks simpleUserHooks {
+                      postConf    = defaultPostConf,
+                      preBuild    = readHook,
+                      preMakefile = readHook,
+                      preClean    = readHook,
+                      preCopy     = readHook,
+                      preInst     = readHook,
+                      preHscolour = readHook,
+                      preHaddock  = readHook,
+                      preReg      = readHook,
+                      preUnreg    = readHook
+                     }
+  where
+    defaultPostConf :: Args -> ConfigFlags -> PackageDescription -> LocalBuildInfo -> IO ()
+    defaultPostConf args flags pkgdescr lbi = do
+      libdir_ <- rawSystemProgramStdoutConf (fromFlag (configVerbosity flags))
+                     ghcProgram (withPrograms lbi) ["--print-libdir"]
+      let libdir = reverse $ dropWhile isSpace $ reverse libdir_
+
+          ghc_pkg = case lookupProgram ghcPkgProgram (withPrograms lbi) of
+                          Just p  -> programPath p
+                          Nothing -> error "ghc-pkg was not found"
+          ghc     = case lookupProgram ghcProgram (withPrograms lbi) of
+                          Just p  -> programPath p
+                          Nothing -> error "ghc was not found"
+
+          -- figure out docdir from base's haddock-html field
+          base_pkg = case searchByName (installedPkgs lbi) "base" of
+                        None -> error "no base package"
+                        Unambiguous (x:_) -> x
+                        _ -> error "base ambiguous"
+          base_html = case haddockHTMLs base_pkg of
+                        [] -> ""
+                        (x:_) -> x
+          docdir = fromMaybe base_html $
+                        fmap reverse (stripPrefix (reverse "/libraries/base")
+                                                  (reverse base_html))
+
+      let buildinfo = emptyBuildInfo{
+               cppOptions = ["-DGHC_PATHS_GHC_PKG=\"" ++ ghc_pkg ++ "\"",
+                             "-DGHC_PATHS_GHC=\"" ++ ghc ++ "\"",
+                             "-DGHC_PATHS_LIBDIR=\"" ++ libdir ++ "\"",
+                             "-DGHC_PATHS_DOCDIR=\"" ++ docdir ++ "\"" ]
+             }
+      writeFile file (show buildinfo)
+
+    readHook :: Args -> a -> IO HookedBuildInfo
+    readHook _ _ = do
+      str <- readFile file
+      return (Just (read str), [])
+
+file = "ghc-paths.buildinfo"
+
+die :: String -> IO a
+die msg = do
+  hFlush stdout
+  hPutStr stderr msg
+  exitWith (ExitFailure 1)
+
diff --git a/ghc-paths.cabal b/ghc-paths.cabal
new file mode 100644
--- /dev/null
+++ b/ghc-paths.cabal
@@ -0,0 +1,15 @@
+name: ghc-paths
+version: 0.1
+license: BSD3
+license-file: LICENSE
+copyright: (c) Simon Marlow
+author: Simon Marlow
+maintainer: Simon Marlow <marlowsd@gmail.com>
+stability: stable
+synopsis: Knowledge of the GHC's installation directories
+category: Development
+cabal-version: >= 1.2
+build-depends: base
+build-type: Custom
+
+exposed-modules: GHC.Paths