diff --git a/Development/Hake.cpphs b/Development/Hake.cpphs
--- a/Development/Hake.cpphs
+++ b/Development/Hake.cpphs
@@ -1,12 +1,14 @@
 module Development.Hake (
   Rule
 , hake
+, hakeT
 , hakefileIs
 
 , file
 , task
 , rule
 , dflt
+, mkfl
 
 , lift
 , systemE
@@ -22,12 +24,17 @@
 import System.Cmd                   (system)
 import System.Directory             (doesFileExist)
 import Control.Applicative          ((<$>))
-import Development.Hake.HiddenTools (isOldThanSomeOf, runHake)
+import Development.Hake.HiddenTools (isOldThanSomeOf, runHake, hakefileUpdateOption)
 import Control.Monad.Reader         (asks, ReaderT(runReaderT), lift)
 #ifdef DEBUG
 import Control.Monad.Reader         (ask)
 #endif /* DEBUG */
-import Control.Monad.Utils          (ifM)
+import Control.Monad.Utils          (ifM, whenM)
+import System.IO.Unsafe             (unsafeInterleaveIO
+#ifdef DEBUG
+                                     , unsafePerformIO
+#endif /* DEBUG */
+                                     )
 
 type Targets   = [ String -> Bool ]
 type Sources   = String -> SourcesRet
@@ -37,7 +44,7 @@
 
 type TargetRet   = String
 type SourcesRet  = [ String ]
-type CommandIO   = ReaderT MadeFromList IO
+type CommandIO   = ReaderT (Bool, MadeFromList) IO
 type CommandRet  = CommandIO ExitCode
 type RuleRet     = ( TargetRet, (SourcesRet, [CommandRet]) )
 
@@ -50,17 +57,28 @@
 ruleRetToMadeFromList = map (\(x, (y, _)) -> (x, y))
 
 hake :: [ Rule ] -> IO ()
-hake rl = getArgs >>= hakeTarget (map ruleToRuleInner rl) . head
+hake rl = do args <- getArgs
+             let ud    = elem hakefileUpdateOption args
+	         args_ = filter (/=hakefileUpdateOption) args
+             case args_ of
+	          [ trgt ] -> hakeTarget ud (map ruleToRuleInner rl) trgt
+		  _        -> error "function (hake): argument error"
 
-hakeTarget :: [ RuleInner ] -> FilePath -> IO ()
-hakeTarget rls fn = do
+hakeT :: [ Rule ] -> FilePath -> IO ()
+hakeT = hakeTarget True . map ruleToRuleInner
+
+hakeTarget :: Bool -> [ RuleInner ] -> FilePath -> IO ()
+hakeTarget ud rls fn = do
   rl <- traceRule fn rls
 #ifdef DEBUG
-  print $ map (map st) rl
+--          >>= return . d (map $ map st)
+--  print $ map (map st) rl
 #endif /* DEBUG */
-  flip runReaderT (ruleRetToMadeFromList $ head rl) $ mapM_ applyRule $ reverse $ head rl
+  flip runReaderT (ud, ruleRetToMadeFromList $ head rl) $ mapM_ applyRule $ reverse $ head rl
 
 #ifdef DEBUG
+d :: Show b => (a -> b) -> a -> a
+d f x = unsafePerformIO $ print (f x) >> return x
 st :: RuleRet -> (TargetRet, SourcesRet)
 st (t, (s, _)) = (t, s)
 #endif /* DEBUG */
@@ -71,10 +89,14 @@
 
 traceRule :: FilePath -> [ RuleInner ] -> IO [[ RuleRet ]]
 traceRule trgt rls
-  = case myLookup trgt rls of
+  =
+#ifdef DEBUG
+ do putStrLn $ "traceRule " ++ show trgt ++ " rls"
+#endif /* DEBUG */
+    case myLookup trgt rls of
       []    ->
 #ifdef DEBUG
-            do exStat <- ifM (doesFileExist trgt) (return "exist") (return " does not exist")
+            do exStat <- ifM (doesFileExist trgt) (return " exist") (return " does not exist")
 	       putStrLn $ "DEBUG (traceRule) : target " ++ trgt ++ exStat
 #endif /* DEBUG */
                ifM (doesFileExist trgt) (return [[]]) (return [])
@@ -83,7 +105,7 @@
         fmap (++optional) $ concat <.> flip mapM finds $ \((tToS, tsToCmds), restRls) -> do
           let srcs = tToS trgt
 	      cmds = tsToCmds trgt srcs
-          obtainedRls <- mapM (flip traceRule restRls) srcs
+          obtainedRls <- mapM (unsafeInterleaveIO . flip traceRule restRls) srcs
 	  return $ map ( (( trgt, (srcs, cmds) ):) . concat ) $ mulLists obtainedRls
 
 mulLists :: [[a]] -> [[a]]
@@ -129,14 +151,24 @@
   = ( [isSuffixOf trgt], \dst -> [changeSuffix trgt src dst ],
       \t [s] -> map systemE $ cmd t s )
 
+mkfl :: ( String, [ String ] ) -> Rule
+mkfl ( trgt, cont )
+  = ( [(==trgt)], const [], \t -> const [ do
+        whenM getUpdateStatus $ do lift $ putStrLn $ "make file `" ++ trgt ++ "' (hake)"
+	                           lift $ writeFile t $ unlines cont
+	return ExitSuccess ] )
+
 hakefileIs :: FilePath -> [ FilePath ] -> IO ExitCode
 hakefileIs src others = do
   args <- getArgs
   runHake src "hake_" others $ if null args then [ "default" ] else args
 
+getUpdateStatus :: CommandIO Bool
+getUpdateStatus = asks fst
+
 getSrcs :: FilePath -> CommandIO [FilePath]
-getSrcs = 
+getSrcs fp = 
 #ifdef DEBUG
-  (ask >>= lift . print >>) .
+--  (ask >>= lift . print >>) .
 #endif /* DEBUG */
-     asks . ( maybe [] id . ) . lookup
+     asks (maybe [] id . lookup fp . snd)
diff --git a/Development/Hake/HiddenTools.cpphs b/Development/Hake/HiddenTools.cpphs
--- a/Development/Hake/HiddenTools.cpphs
+++ b/Development/Hake/HiddenTools.cpphs
@@ -1,6 +1,7 @@
 module Development.Hake.HiddenTools (
   runHake
 , isOldThanSomeOf
+, hakefileUpdateOption
 ) where
 
 import System.Directory     (createDirectory, doesDirectoryExist,
@@ -10,7 +11,8 @@
 import System.Time          (ClockTime)
 import System.IO            (openFile, hClose, IOMode(WriteMode))
 import Control.Applicative  ((<$>), liftA2)
-import Control.Monad.Utils  (whenM, unlessM)
+import Control.Monad        (when)
+import Control.Monad.Utils  (unlessM)
 import Control.Exception    (bracket)
 
 maybeGetModificationTime :: FilePath -> IO (Maybe ClockTime)
@@ -28,13 +30,19 @@
       myOr [] = True
       myOr bs = or bs
 
+hakefileUpdateOption :: String
+hakefileUpdateOption = "--hakefile-is-updated"
+
 runHake :: FilePath -> FilePath -> [ FilePath ] -> [ String ] -> IO ExitCode
-runHake src exe otrs args = do
+runHake src exe othrs args = do
   unlessM (doesDirectoryExist "_hake") $ createDirectory "_hake"
-  flip mapM_ otrs $ \fn -> do
+  othrsUD <- fmap or $ flip mapM othrs $ \fn -> do
     let dist = "_hake/" ++ basename fn
-    whenM (isOldThanSomeOf dist [ fn ]) $ copyFile fn dist
-  whenM (isOldThanSomeOf ("_hake/" ++ exe ++ ".hs") [ src ]) $
+    updated <- isOldThanSomeOf dist [ fn ]
+    when updated $ copyFile fn dist
+    return updated
+  hakefileUD <- isOldThanSomeOf ("_hake/" ++ exe ++ ".hs") [ src ]
+  when hakefileUD $
     readFile src >>= writeFile ("_hake/" ++ exe ++ ".hs")
 #ifndef DEBUG
   bracket (flip openFile WriteMode $ "_hake/" ++ exe ++ ".error") hClose $ \errH ->
@@ -44,7 +52,8 @@
 #endif /* DEBUG */
       runProcess "ghc" [ "--make", exe ] (Just "_hake")
                  Nothing Nothing Nothing mErrH >>= waitForProcess
-  runProcess ("_hake/" ++ exe) (if null args then ["default"] else args)
+  let args_ = if othrsUD || hakefileUD then (hakefileUpdateOption:args) else args
+  runProcess ("_hake/" ++ exe) (if null args then ("default":args_) else args_)
              Nothing Nothing Nothing Nothing Nothing >>= waitForProcess
 
 basename :: FilePath -> FilePath
diff --git a/Main.hs b/Main.hs
--- a/Main.hs
+++ b/Main.hs
@@ -1,9 +1,13 @@
 module Main where
 
 import System.Environment           (getArgs)
-import System.Exit                  (ExitCode)
+import System.Exit                  (ExitCode(ExitSuccess))
 import Development.Hake.HiddenTools (runHake)
+import Paths_hake                   (version)
+import Data.Version                 (showVersion)
 
 main :: IO ExitCode
 main = do args <- getArgs
-          runHake "Hakefile" "hake" [] (if null args then ["default"] else args)
+          case args of
+	    [ "--version" ] -> putStrLn ("hake " ++ showVersion version) >> return ExitSuccess
+            _               -> runHake "Hakefile" "hake" [] (if null args then ["default"] else args)
diff --git a/hake.cabal b/hake.cabal
--- a/hake.cabal
+++ b/hake.cabal
@@ -1,5 +1,5 @@
 Name:		hake
-Version:	0.1
+Version:	0.2
 License:	GPL
 License-file:	LICENSE
 Author:		Yoshikuni Jujo
@@ -15,7 +15,7 @@
 		then you can use all Haskell features.
 		.
 		> import Development.Hake
-		> hake_tree = [
+		> hake_rules = [
 		>
 		>  dflt	[ "greeting" ]
 		>  ,
@@ -29,6 +29,8 @@
 		> 		\t s -> [ "compiler2 " ++ s ++ " -o " ++ t ] )
 		>  ,
 		>  task	( "clean" , [ "rm -f *.o greeting greeting.log" ] )
+		>  ,
+		>  mkfl ( "script.sh", [ "#!/bin/sh", "echo This is script", "echo made by Hakefile" ] )
 		>
 		>  ]
 		>
@@ -36,7 +38,7 @@
 
 Stability:	experimental
 Homepage:	http://homepage3.nifty.com/salamander/second/projects/hake/index.xhtml
-Package-Url:	http://homepage3.nifty.com/salamander/second/portage/distfiles/hake-0.0.tar.gz
+Package-Url:	http://homepage3.nifty.com/salamander/second/portage/distfiles/hake-0.2.tar.gz
 Cabal-Version:	>= 1.2
 Build-type:	Simple
 Tested-With:	GHC