diff --git a/Data/Graph/Inductive/Query/Ear.hs b/Data/Graph/Inductive/Query/Ear.hs
new file mode 100644
--- /dev/null
+++ b/Data/Graph/Inductive/Query/Ear.hs
@@ -0,0 +1,88 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TupleSections #-}
+
+-- | Ear decomposition of a graph.
+
+module Data.Graph.Inductive.Query.Ear where
+
+import Data.Function
+import Data.Graph.Inductive.Basic
+import Data.Graph.Inductive.Example
+import Data.Graph.Inductive.Graph
+import Data.Graph.Inductive.Query
+import Data.Graph.Inductive.Tree
+import Data.List
+import Data.Tree
+import Data.Tuple
+
+
+
+-- | The 'ears' function takes a graph with no node or edge annotation and
+-- produces an ear decomposition. Each edge is annotated with a weight. Edges
+-- with the same weight are in the same ear.
+
+ears :: forall gr . DynGraph gr => gr () () -> gr () Int
+ears g
+  | isConnected g = gWs
+  | otherwise = error "called ears on disconnected graph"
+  where
+    t :: Tree Node
+    [t] = dff' g
+    tps = treeToPaths t
+    te = treeToEdges t
+    g' = mkUGraph (nodes g) ((edges g \\ te) \\ (map swap te)) `asTypeOf` g
+    -- gE is the graph of all edges not in the spanning tree. The edge weight
+    -- is the distance between the tree root and the lowest common ancestor of
+    -- the two nodes making up each edge
+    gE :: gr () Int  = mkGraph (labNodes g') (map (lca tps) $ labEdges g')
+    gE'  = mkGraph (labNodes gE) (labEdges gE ++ map (\(a,b) -> (a,b,0)) (te ++ map swap te))
+    teWs = map (shortestPaths gE') te
+    gWs  = mkGraph (labNodes g') (labEdges gE ++ teWs ++ map swap12 teWs)
+
+shortestPaths :: Gr () Int -> Edge -> LEdge Int
+shortestPaths g (u,v) = (u,v,spLength u v g') where
+  g' = delEdge (u,v) $ delEdge (v,u) g
+
+lca :: [[Node]] -> (LEdge ()) -> (LEdge Int)
+lca ps (u,v,())
+  | any null ps = error $ "null path: " ++ show ps
+  | otherwise = (u,v,) . (subtract 1) . length . filter (uncurry (==)) $ zip u' v' where
+  [u'] = filter ((==u) . last) ps
+  [v'] = filter ((==v) . last) ps
+
+swap12 (a,b,c) = (b,a,c)
+
+sel3 (_,_,s) = s
+
+-- tree edges
+
+treeToEdges :: Tree Node -> [Edge]
+treeToEdges (Node _ []) = []
+treeToEdges (Node k xs) = map ((k,) . rootLabel) xs ++ concatMap treeToEdges xs
+
+-- paths
+treeToPaths :: Tree Node -> [[Node]]
+treeToPaths (Node k []) = [[k]]
+treeToPaths (Node k xs) = [[k]] ++ [ (k:ys) | ys <- concatMap treeToPaths xs ]
+
+
+
+{-
+ - Test graph
+ -
+
+fig13 :: Gr () ()
+fig13 = undir $ mkUGraph ns es where
+  ns = [1..9]
+  es = [ (1,2),(1,4)
+       , (2,3),(2,5)
+       , (3,4),(3,6)
+       , (4,7)
+       , (5,6),(5,8)
+       , (6,7)
+       , (7,9)
+       , (8,9)
+       ]
+
+-}
+
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Christian Hoener zu Siederdissen 2013
+
+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 Christian Hoener zu Siederdissen 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
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/fgl-extras-decompositions.cabal b/fgl-extras-decompositions.cabal
new file mode 100644
--- /dev/null
+++ b/fgl-extras-decompositions.cabal
@@ -0,0 +1,40 @@
+Name:           fgl-extras-decompositions
+Version:        0.1.0.0
+License:        BSD3
+License-file:   LICENSE
+Author:         Christian Hoener zu Siederdissen
+Maintainer:     choener@tbi.univie.ac.at
+Copyright:      Christian Hoener zu Siederdissen, 2013
+Homepage:       http://www.tbi.univie.ac.at/~choener/
+Stability:      Experimental
+Category:       Data
+Build-type:     Simple
+Cabal-version:  >=1.6
+Synopsis:
+                Graph decomposition algorithms
+Description:
+                Graph decompositions of fgl graphs. This library is rather
+                experimental.
+                .
+                Currently:
+                .
+                - ear decomposition
+                .
+                .
+                .
+                Patches and ideas welcome.
+
+Library
+  Exposed-modules:
+    Data.Graph.Inductive.Query.Ear
+  Build-depends:
+    base        >= 4 && <5  ,
+    containers              ,
+    fgl         >= 5.4
+  ghc-options:
+    -O2
+
+source-repository head
+  type: git
+  location: git://github.com/choener/fgl-extras-decompositions
+