diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright (c) 2015, Markus Aronsson
+
+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 Markus Aronsson 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/observable-sharing.cabal b/observable-sharing.cabal
new file mode 100644
--- /dev/null
+++ b/observable-sharing.cabal
@@ -0,0 +1,29 @@
+-- Initial observable-sharing.cabal generated by cabal init.  For further 
+-- documentation, see http://haskell.org/cabal/users-guide/
+
+name:                observable-sharing
+version:             0.1.0.0
+synopsis:            Simple observable sharing
+-- description:         
+license:             BSD3
+license-file:        LICENSE
+author:              Atze van Der Ploeg <atzeus@gmail.com>,
+                     Markus Aronsson <mararon@chalmers.se>
+maintainer:          mararon@chalmers.se
+-- copyright:           
+category:            Data
+build-type:          Simple
+-- extra-source-files:  
+cabal-version:       >=1.10
+
+source-repository head
+  type:     git
+  location: git://github.com/atzeus/observable-sharing
+
+library
+  exposed-modules:     Data.Ref
+  -- other-modules:       
+  -- other-extensions:    
+  build-depends:       base >=4.8 && <4.9
+  hs-source-dirs:      .,src
+  default-language:    Haskell2010
diff --git a/src/Data/Ref.hs b/src/Data/Ref.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Ref.hs
@@ -0,0 +1,24 @@
+module Data.Ref where
+
+import Data.Unique
+import System.IO.Unsafe
+import Control.Applicative
+
+--------------------------------------------------------------------------------
+-- * References
+--------------------------------------------------------------------------------
+
+data Ref a = Ref { refNr :: Unique , deref :: a }
+
+instance Eq (Ref a) where
+  Ref u1 _ == Ref u2 _ = u1 == u2
+
+instance Show a => Show (Ref a) where
+  show (Ref u x) = "(Ref " ++ show (hashUnique u) ++ " " ++ show x ++ ")"
+
+ref :: a -> Ref a
+ref x = unsafePerformIO $ flip Ref x <$> newUnique
+{-# NOINLINE ref #-}
+
+--------------------------------------------------------------------------------
+-- the end.