diff --git a/pkgs/applications/networking/sync/unison/default.nix b/pkgs/applications/networking/sync/unison/default.nix
new file mode 100644
index 000000000000..de9d7aabc6d3
--- /dev/null
+++ b/pkgs/applications/networking/sync/unison/default.nix
@@ -0,0 +1,27 @@
+{stdenv, fetchurl, ocaml, lablgtk, fontschumachermisc, xset, makeWrapper}:
+
+stdenv.mkDerivation {
+  name = "unison-2.13.16";
+  src = fetchurl {
+    url = http://www.seas.upenn.edu/~bcpierce/unison//download/releases/stable/unison-2.13.16.tar.gz;
+    sha256 = "808400a933aeb67654edc770822cd186d1b2adc92e7cb5836996c71c69ffe656";
+  };
+
+  buildInputs = [ocaml];
+
+  addInputsHook = "source $makeWrapper";
+  preBuild = "sed -i \"s|\\(OCAMLOPT=.*\\)$|\\1 -I $lablgtk/lib/ocaml/lablgtk2|\" Makefile.OCaml";
+  makeFlags = "UISTYLE=gtk2 INSTALLDIR=$(out)/bin/";
+  preInstall = "ensureDir $out/bin";
+  postInstall = [
+    "for i in $(cd $out/bin && ls); do"
+    "   mv $out/bin/$i $out/bin/.orig-$i;"
+    "   echo \"#! $SHELL -e\" > $out/bin/$i;"
+    "   echo \"$xset/bin/xset q | grep -q \\\"$fontschumachermisc\\\" || $xset/bin/xset +fp \\\"$fontschumachermisc/lib/X11/fonts/misc\\\"\" >> $out/bin/$i;"
+    "   echo \"exec \\\"$out/bin/.orig-$i\\\" \\\"\\\$@\\\"\" >> $out/bin/$i;"
+    "   chmod +x $out/bin/$i;"
+    "done"
+  ];
+
+  inherit lablgtk fontschumachermisc xset makeWrapper;
+}
diff --git a/pkgs/development/libraries/lablgtk/default.nix b/pkgs/development/libraries/lablgtk/default.nix
new file mode 100644
index 000000000000..12728717e82c
--- /dev/null
+++ b/pkgs/development/libraries/lablgtk/default.nix
@@ -0,0 +1,14 @@
+{stdenv, fetchurl, ocaml, pkgconfig, gtk}:
+
+stdenv.mkDerivation {
+  name = "lablgtk-2.6.0";
+  src = fetchurl {
+    url = http://wwwfun.kurims.kyoto-u.ac.jp/soft/olabl/dist/lablgtk-2.6.0.tar.gz;
+    sha256 = "3694bc1e288ce0903af6c96a2790d2340ba38fa51b18090062ede75137d97876";
+  };
+
+  buildInputs = [ocaml pkgconfig gtk];
+
+  configureFlags = "--with-libdir=$(out)/lib/ocaml";
+  buildFlags = "world";
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 6f28dbcfaefd..30e05ef3be92 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1506,6 +1506,11 @@ rec {
     inherit fetchurl stdenv x11 libjpeg libtiff libungif libpng;
   };
 
+  lablgtk = import ../development/libraries/lablgtk {
+    inherit fetchurl stdenv ocaml pkgconfig;
+    inherit (gtkLibs) gtk;
+  };
+
   lcms = import ../development/libraries/lcms {
     inherit fetchurl stdenv;
   };
@@ -3312,6 +3317,11 @@ rec {
     #enableOfficialBranding = true;
   };
 
+  unison = import ../applications/networking/sync/unison {
+    inherit fetchurl stdenv ocaml lablgtk makeWrapper;
+    inherit (xorg) xset fontschumachermisc;
+  };
+
   valknut = import ../applications/networking/p2p/valknut {
     inherit fetchurl stdenv perl x11 libxml2 libjpeg libpng openssl dclib;
     qt = qt3;