diff --git a/pkgs/applications/science/logic/ott/default.nix b/pkgs/applications/science/logic/ott/default.nix
new file mode 100644
index 000000000000..afe827f3ad98
--- /dev/null
+++ b/pkgs/applications/science/logic/ott/default.nix
@@ -0,0 +1,43 @@
+# - coqide compilation can be disabled by setting lablgtk to null;
+
+{stdenv, fetchurl, pkgconfig, ocaml, camlp5}:
+
+stdenv.mkDerivation rec {
+  name = "ott-${version}";
+  version = "0.25";
+
+  src = fetchurl {
+    url = "http://www.cl.cam.ac.uk/~pes20/ott/ott_distro_${version}.tar.gz";
+    sha256 = "0i8ad1yrz9nrrgpi8db4z0aii5s0sy35mmzdfw5nq183mvbx8qqd";
+  };
+
+  buildInputs = [ pkgconfig ocaml camlp5 ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    cp src/ott.opt $out/bin
+    ln -s $out/bin/ott.opt $out/bin/ott
+
+    mkdir -p $out/share/emacs/site-lisp
+    cp emacs/ottmode.el $out/share/emacs/site-lisp
+    '';
+
+  meta = {
+    description = "Ott: tool for the working semanticist";
+    longDescription = ''
+      Ott is a tool for writing definitions of programming languages and
+      calculi. It takes as input a definition of a language syntax and
+      semantics, in a concise and readable ASCII notation that is close to
+      what one would write in informal mathematics. It generates LaTeX to
+      build a typeset version of the definition, and Coq, HOL, and Isabelle
+      versions of the definition. Additionally, it can be run as a filter,
+      taking a LaTeX/Coq/Isabelle/HOL source file with embedded (symbolic)
+      terms of the defined language, parsing them and replacing them by
+      target-system terms.
+    '';
+    homepage = http://www.cl.cam.ac.uk/~pes20/ott;
+    license = "BSD3";
+    maintainers = with stdenv.lib.maintainers; [ jwiegley ];
+    platforms = stdenv.lib.platforms.unix;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 1c9fb7018c95..1d4a6b59a0c9 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -11264,6 +11264,10 @@ let
 
   opensmt = callPackage ../applications/science/logic/opensmt { };
 
+  ott = callPackage ../applications/science/logic/ott {
+    camlp5 = ocamlPackages.camlp5_transitional;
+  };
+
   otter = callPackage ../applications/science/logic/otter {};
 
   picosat = callPackage ../applications/science/logic/picosat {};