diff --git a/ghc-core.cabal b/ghc-core.cabal
--- a/ghc-core.cabal
+++ b/ghc-core.cabal
@@ -1,5 +1,5 @@
 name:           ghc-core
-version:        0.1
+version:        0.2
 license:        BSD3
 license-file:   LICENSE
 author:         Don Stewart
diff --git a/ghc-core.hs b/ghc-core.hs
--- a/ghc-core.hs
+++ b/ghc-core.hs
@@ -26,7 +26,9 @@
 import Control.Exception
 import Control.Monad
 import Data.List
+import Data.Maybe
 import System.Cmd
+import System.Console.GetOpt
 import System.Directory
 import System.Environment
 import System.Exit
@@ -42,37 +44,70 @@
 import Language.Haskell.HsColour.Colourise
 
 ------------------------------------------------------------------------
+--
+-- Command line parsing
+--
 
--- default hscolours
-defaultColourPrefs :: ColourPrefs
-defaultColourPrefs = ColourPrefs
-  { keyword  = [Foreground Green,Underscore]
-  , keyglyph = [Foreground Red]
-  , layout   = [Foreground Cyan]
-  , comment  = [Foreground Blue]
-  , conid    = [Normal]
-  , varid    = [Normal]
-  , conop    = [Foreground Red,Bold]
-  , varop    = [Foreground Cyan]
-  , string   = [Foreground Magenta]
-  , char     = [Foreground Magenta]
-  , number   = [Foreground Magenta]
-  , cpp      = [Foreground Magenta,Dim]
-  , selection = [Bold, Foreground Magenta]
-  , variantselection = [Dim, Foreground Red, Underscore]
-  , definition = [Foreground Blue]
+data Options = Options
+  { optHelp   :: Bool
+  , optFormat :: Output
+  , optGhcExe :: String
+  } deriving (Eq, Show)
+
+defaultOptions :: Options
+defaultOptions = Options
+  { optHelp    = False
+  , optFormat  = TTY
+  , optGhcExe  = "ghc"
   }
 
+formats :: [(String, Output)]
+formats = [("css", CSS), ("html", HTML), ("tty", TTY)]
+
+options :: [OptDescr (Options -> Options)]
+options =
+    [   Option ['f'] ["format"] 
+            (ReqArg (\x opts -> opts { optFormat = fromString x }) "FORMAT")
+            ("Output format " ++ formats' ++ ".")
+        ,Option ['h'] ["help"]
+            (NoArg (\opts -> opts { optHelp = True }))
+            "Print this help message."
+        ,Option [] ["with-ghc"]
+            (ReqArg (\x opts -> opts { optGhcExe = x }) "PROGRAM")
+            "Ghc executable to use."
+    ]
+    where
+        fromString  f = fromMaybe (formatError f) (lookup f formats)
+        formatError f = error $
+                            "invalid format `" ++ f ++ "'"
+                            ++ ", must be one of " ++ formats' ++ "."
+        formats' = "(" ++ concat (intersperse ", " (map fst formats)) ++ ")"
+
+parseOptions :: [String] -> IO (Options, [String])
+parseOptions argv = 
+    case getOpt RequireOrder options argv of
+        (o, n, []) -> let o' = foldl (flip ($)) defaultOptions o in
+                        if optHelp o'
+                            then do hPutStr stderr (usageInfo header options)
+                                    exitWith ExitSuccess
+                            else return (o', n)
+        (_, _, es) -> ioError (userError (concat es ++ usageInfo header options))
+    where header = "Usage: ghc-core [OPTION...] [--] [GHC_OPTION...] [files...]"
+
 ------------------------------------------------------------------------
 
 main :: IO ()
 main = do
-    args  <- getArgs
+    -- Parse command line
+    (opts, args) <- getArgs >>= parseOptions
 
+    -- Read colors from .hscolour
+    colourPrefs <- readColourPrefs
+
     mv <- getEnvMaybe "PAGER"
     let less = case mv of Just s -> s ; _ -> "less"
 
-    strs' <- polish `fmap` compileWithCore args
+    strs' <- polish `fmap` compileWithCore (optGhcExe opts) args
     (strs,tmps) <- do
         x <- readProcess "sh" ["-c","ls /tmp/ghc*/*.s | head -1"] []
         case x of
@@ -82,7 +117,9 @@
                                     return ((strs' ++ asm), Just $ takeDirectory s)
                             else return (strs', Just $ takeDirectory s)
 
-    let nice = hscolour TTY defaultColourPrefs False True False strs
+    let nice = hscolour
+                (optFormat opts)
+                colourPrefs False True False strs
 
     bracket
         (openTempFile "/tmp" "ghc-core-XXXX.hcr")
@@ -148,10 +185,9 @@
 
 ------------------------------------------------------------------------
 
-compileWithCore :: [String] -> IO String
-compileWithCore opts = do
-    let ghc  = "ghc"
-        args = words "-O2 -keep-tmp-files -ddump-simpl -ddump-asm -ddump-simpl-stats -no-recomp --make"
+compileWithCore :: String -> [String] -> IO String
+compileWithCore ghc opts = do
+    let args = words "-O2 -keep-tmp-files -ddump-simpl -ddump-asm -ddump-simpl-stats -no-recomp --make"
 
     x <- readProcess ghc (opts ++ args) []
     case x of