diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright (c) 2012, Sönke Hahn
+
+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 the name of Sönke Hahn nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 COPYRIGHT
+OWNER OR 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
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/darcs2dot.cabal b/darcs2dot.cabal
new file mode 100644
--- /dev/null
+++ b/darcs2dot.cabal
@@ -0,0 +1,35 @@
+-- Initial darcs2dot.cabal generated by cabal init.  For further 
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+name:                darcs2dot
+version:             0.1.0.0
+synopsis:            Outputs dependencies of darcs patches in dot format.
+description:
+    Outputs dependencies of darcs patches in dot format. Just run darcs2dot in a darcs repo and it will output (the transitive reduction of) the dependencies of the patches in dot format to stdout.
+    .
+    You can use the graphviz tools to generate graph files from that. For example:
+    .
+    @$ darcs2dot | dot -Tpdf -o darcsDeps.pdf@
+
+license:             BSD3
+license-file:        LICENSE
+author:              Sönke Hahn
+maintainer:          soenkehahn@gmail.com
+-- copyright:           
+category:            Development
+build-type:          Simple
+cabal-version:       >=1.8
+
+source-repository head
+    type:     darcs
+    location: shahn@patch-tag.com:/r/shahn/darcs2dot
+
+executable darcs2dot
+  main-is: darcs2dot.hs
+  build-depends:
+    base ==4.5.*,
+    darcs == 2.8.*,
+    string-conversions == 0.2.*,
+    containers == 0.4.*,
+    graph-wrapper == 0.2.*
+
diff --git a/darcs2dot.hs b/darcs2dot.hs
new file mode 100644
--- /dev/null
+++ b/darcs2dot.hs
@@ -0,0 +1,99 @@
+#!/usr/bin/env runhaskell
+
+{-# language GADTs, TypeOperators, ViewPatterns, FlexibleContexts, ScopedTypeVariables #-}
+
+
+import Data.Graph.Wrapper
+import Data.Map (Map, (!))
+import qualified Data.Map as Map
+import Data.String.Conversions
+
+import Text.Printf
+
+import Control.Applicative
+
+import Darcs.Repository
+import Darcs.Witnesses.Ordered
+import Darcs.Patch.Named
+import Darcs.Patch.Info
+import Darcs.Patch.Choices
+import Darcs.Patch.Patchy
+
+
+main = withRepository [] $ RepoJob $ \ repo ->
+    putStr . toDot . dependencies . patchSetToPatches =<< readRepo repo
+
+
+dependencies :: Patchy (Named p) => FL (Named p) x y -> Graph Tag String
+dependencies fl =
+    let choices = patchChoices fl
+        tags = getNamedTags choices
+    in fromList $ flip map tags $ \ (name, tag) ->
+        let firsts = getFirsts $ forceFirst tag choices
+            depends = filter (\ (n, t) -> t /= tag) firsts
+        in (tag, name, map snd depends) :: (Tag, String, [Tag])
+
+
+type NamedTag = (String, Tag)
+
+getFirsts :: Patchy (Named p) => PatchChoices (Named p) x y -> [NamedTag]
+getFirsts (getChoices -> (a :> _)) = getTagsFL a
+
+getNamedTags :: Patchy (Named p) => PatchChoices (Named p) x y -> [NamedTag]
+getNamedTags (getChoices -> (a :> (b :> c))) =
+    getTagsFL a ++
+    getTagsFL b ++
+    getTagsFL c
+
+getTagsFL :: FL (TaggedPatch (Named p)) x y -> [(String, Tag)]
+getTagsFL NilFL = []
+getTagsFL (a :>: b) = e : getTagsFL b
+  where
+    e = (cs . _piName . patch2patchinfo . tpPatch $ a, tag a)
+
+-- not used
+showChoices :: Patchy (Named p) => PatchChoices (Named p) x y -> String
+showChoices choices =
+    case getChoices choices of
+        (a :> (b :> c)) -> showFL a ++ " :> (" ++ showFL b ++ " :> " ++ showFL c ++ ")"
+
+-- not used
+showFL :: FL (TaggedPatch (Named p)) x y -> String
+showFL fl =
+    case mapFL (cs . _piName . patch2patchinfo . tpPatch) fl of
+         [] -> "[]"
+         x -> unwords x
+
+
+-- * graph stuff
+
+transitiveReduction :: Ord i => Graph i v -> Graph i v
+transitiveReduction g =
+    fromList $ map inner $ toList g
+  where
+    inner (i, v, outgoing) =
+        (i, v, filter (\ o -> not $ hasIndirectPath i o) outgoing)
+    hasIndirectPath a b = any (\ m -> a ~> m && m ~> b) (vertices g)
+    a ~> b = b `elem` successors g a
+
+
+-- * dot
+
+toDot :: (Ord i) => Graph i String -> String
+toDot graph =
+    "digraph g {\n" ++
+        (concatMap inner $ toList $ fmap (take 15) $ transitiveReduction $ indexToInt graph) ++
+    "}\n"
+  where
+    inner (i, name, outgoing) =
+        printf "    %i [label = \"%s\"];\n" i name ++
+        concatMap (\ out -> printf "    %i -> %i;\n" i out) outgoing
+
+-- | convert indices to Ints
+indexToInt :: forall i v . Ord i => Graph i v -> Graph Int v
+indexToInt g =
+    fromList $ map inner $ toList g
+  where
+    inner (i, v, outgoing) = (intMap ! i, v, map (intMap !) outgoing)
+    intMap :: Map i Int
+    intMap = Map.fromList $ zip (vertices g) [0..]