diff --git a/data.zip b/data.zip
Binary files a/data.zip and b/data.zip differ
diff --git a/orchid-demo.cabal b/orchid-demo.cabal
--- a/orchid-demo.cabal
+++ b/orchid-demo.cabal
@@ -1,5 +1,5 @@
 Name:             orchid-demo
-Version:          0.0.4
+Version:          0.0.5
 Description:      Haskell Wiki Demo
 Synopsis:         Haskell Wiki Demo
 Category:         Network, Web
@@ -10,8 +10,9 @@
 Build-Type:       Simple
 Build-Depends:    base,
                   network,
-                  salvia ==0.0.4,
-                  orchid ==0.0.6,
+                  extensible-exceptions,
+                  salvia ==0.0.5,
+                  orchid ==0.0.7,
                   mtl ==1.1.0.2,
                   Pipe,
                   stm
diff --git a/src/Demo.hs b/src/Demo.hs
--- a/src/Demo.hs
+++ b/src/Demo.hs
@@ -1,24 +1,22 @@
 module Main where
 
 import Control.Concurrent.STM
+import Control.Exception.Extensible
 import Control.Monad (when)
-import Control.Exception
-import System.Exit
-import System.IO
-import System.Environment
-import System.Console.GetOpt
-import System.Process.Pipe
-import Network.Socket (PortNumber, inet_addr)
-
+import Network.Orchid.Wiki (hWiki, FileStoreType (..))
 import Network.Protocol.Uri (jail)
+import Network.Salvia.Advanced.ExtendedFileSystem (hExtendedFileSystem)
 import Network.Salvia.Handlers.Default (hDefault)
 import Network.Salvia.Handlers.Login (readUserDatabase, UserPayload)
 import Network.Salvia.Handlers.Session (mkSessions, Sessions)
-import Network.Salvia.Advanced.ExtendedFileSystem (hExtendedFileSystem)
 import Network.Salvia.Httpd (defaultConfig, start, listenAddr, listenPort)
-import Network.Orchid.Wiki (hWiki)
-
+import Network.Socket (PortNumber, inet_addr)
 import Paths_orchid_demo
+import System.Console.GetOpt
+import System.Environment
+import System.Exit
+import System.IO
+import System.Process.Pipe
 
 -------------------------------------------------------------------------------
 
@@ -34,17 +32,21 @@
 
   -- Run web server with wiki.
   run
-    (asServer conf)
-    (bindAddr conf)
-    (bindPort conf)
-    (dataDir  conf)
-    (userDB   conf)
+    (asServer  conf)
+    (filestore conf)
+    (bindAddr  conf)
+    (bindPort  conf)
+    (dataDir   conf)
+    (userDB    conf)
 
 -------- wiki server ----------------------------------------------------------
 
-run :: Bool -> String -> PortNumber -> FilePath -> FilePath -> IO ()
-run serve address port dir users = do
+stringToFileStore :: String -> Maybe FileStoreType
+stringToFileStore kind = lookup kind [("Darcs", Darcs), ("Git", Git)]
 
+run :: Bool -> String -> String -> PortNumber -> FilePath -> FilePath -> IO ()
+run serve sfs address port dir users = do
+
   -- Initialize global state.
   db       <- readUserDatabase users
   ioconfig <- defaultConfig 
@@ -52,24 +54,28 @@
   sessions <- mkSessions :: IO (Sessions (UserPayload ()))
   addr     <- inet_addr address
 
-  -- Alter config and setup handler.
-  let config    = ioconfig { listenAddr = addr, listenPort = port }
-  let myHandler = if serve
-                   then const $ hExtendedFileSystem dir
-                   else hWiki dir dir db
+  case stringToFileStore sfs of
+    Nothing -> putStrLn $ "Error: No such filestore: " ++ sfs
+    Just fs -> do
 
-  -- Warn about serving user database.
-  when (maybe False (const True) (jail dir users))
-    $ putStrLn "Warning: serving user database to the evil outside world."
+      -- Alter config and setup handler.
+      let config    = ioconfig { listenAddr = addr, listenPort = port }
+      let myHandler = if serve
+                       then const $ hExtendedFileSystem dir
+                       else hWiki fs dir dir db
 
-  -- Print status messages and..
-  putStrLn $ concat ["Listening on ", address, ":", show (listenPort config), "."]
-  putStrLn $ concat ["Using ", dir, " as wiki repository."]
+      -- Warn about serving user database.
+      when (maybe False (const True) (jail dir users))
+        $ putStrLn "Warning: serving user database to the evil outside world."
 
-  -- ..off we go!
-  putStrLn "Server started."
-  start config $ hDefault count sessions myHandler
+      -- Print status messages and..
+      putStrLn $ concat ["Listening on ", address, ":", show (listenPort config), "."]
+      putStrLn $ concat ["Using ", dir, " as wiki repository."]
 
+      -- ..off we go!
+      putStrLn "Server started."
+      start config $ hDefault count sessions myHandler
+
 extractArchive :: FilePath -> FilePath -> IO ()
 extractArchive from to = do
   putStrLn $ concat ["Extracting repository from ", from, " to ", to, "."]
@@ -88,6 +94,7 @@
   , dataDir     :: String
   , userDB      :: String
   , asServer    :: Bool
+  , filestore   :: String
   , bindAddr    :: String
   , bindPort    :: PortNumber
   } deriving Show
@@ -104,6 +111,7 @@
     , dataDir     = "/tmp/data"
     , userDB      = "/tmp/data/_user.db"
     , asServer    = False
+    , filestore   = "Darcs"
     , bindAddr    = "0.0.0.0"
     , bindPort    = 8080
     } 
@@ -118,6 +126,7 @@
     optDataDir     = OptArg (maybe id (\a c -> c { dataDir     = a    })) "/tmp/data"
     optUserDB      = OptArg (maybe id (\a c -> c { userDB      = a    })) "/tmp/data/_user.db"
     optAsServer    = NoArg            (\  c -> c { asServer    = True }) 
+    optFileStore   = OptArg (maybe id (\a c -> c { filestore   = a    })) "Darcs"
     optBindAddr    = OptArg (maybe id (\a c -> c { bindAddr    = a    })) "0.0.0.0"
     optBindPort    = OptArg (maybe id (\a c -> c { bindPort    = fromIntegral (read a :: Int) })) "8080"
   in [
@@ -127,6 +136,7 @@
   , Option [] ["data-dir"]   optDataDir     "run demo with this repository"
   , Option [] ["user-db"]    optUserDB      "location of user database file"
   , Option [] ["as-server"]  optAsServer    "do not start wiki but serve directory"
+  , Option [] ["filestore"]  optFileStore   "filestore type: Darcs or Git"
   , Option [] ["address"]    optBindAddr    "address to listen on"
   , Option [] ["port"]       optBindPort    "port to bind to"
   ]