diff --git a/pkgs/applications/science/logic/fast-downward/default.nix b/pkgs/applications/science/logic/fast-downward/default.nix
new file mode 100644
index 000000000000..21ce6be3e6c1
--- /dev/null
+++ b/pkgs/applications/science/logic/fast-downward/default.nix
@@ -0,0 +1,55 @@
+{ stdenv, lib, fetchhg, cmake, which, python3, osi, cplex }:
+
+stdenv.mkDerivation rec {
+  name = "fast-downward-2019-05-13";
+
+  src = fetchhg {
+    url = "http://hg.fast-downward.org/";
+    rev = "090f5df5d84a";
+    sha256 = "14pcjz0jfzx5269axg66iq8js7lm2w3cnqrrhhwmz833prjp945g";
+  };
+
+  nativeBuildInputs = [ cmake which ];
+  buildInputs = [ python3 python3.pkgs.wrapPython osi ];
+
+  cmakeFlags =
+    lib.optional osi.withCplex [ "-DDOWNWARD_CPLEX_ROOT=${cplex}/cplex" ];
+
+  enableParallelBuilding = true;
+
+  postPatch = ''
+    cd src
+    # Needed because the package tries to be too smart.
+    export CC="$(which $CC)"
+    export CXX="$(which $CXX)"
+  '';
+
+  installPhase = ''
+    install -Dm755 bin/downward $out/libexec/fast-downward/downward
+    cp -r ../translate $out/libexec/fast-downward/
+    install -Dm755 ../../fast-downward.py $out/bin/fast-downward
+    mkdir -p $out/${python3.sitePackages}
+    cp -r ../../driver $out/${python3.sitePackages}
+
+    wrapPythonProgramsIn $out/bin "$out $pythonPath"
+    wrapPythonProgramsIn $out/libexec/fast-downward/translate "$out $pythonPath"
+    # Because fast-downward calls `python translate.py` we need to return wrapped scripts back.
+    for i in $out/libexec/fast-downward/translate/.*-wrapped; do
+      name="$(basename "$i")"
+      name1="''${name#.}"
+      name2="''${name1%-wrapped}"
+      dir="$(dirname "$i")"
+      dest="$dir/$name2"
+      echo "Moving $i to $dest"
+      mv "$i" "$dest"
+    done
+  '';
+
+  meta = with stdenv.lib; {
+    description = "A domain-independent planning system";
+    homepage = "http://www.fast-downward.org/";
+    license = licenses.gpl3Plus;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ abbradar ];
+  };
+}
diff --git a/pkgs/applications/science/math/cplex/default.nix b/pkgs/applications/science/math/cplex/default.nix
index dc0e9ea1aa5d..a14839d3eccc 100644
--- a/pkgs/applications/science/math/cplex/default.nix
+++ b/pkgs/applications/science/math/cplex/default.nix
@@ -71,6 +71,11 @@ stdenv.mkDerivation rec {
       fi
     done
   '';
+
+  passthru = {
+    libArch = "x86-64_linux";
+    libSuffix = "${version}0";
+  };
   
   meta = with stdenv.lib; {
     description = "Optimization solver for mathematical programming";
diff --git a/pkgs/applications/science/math/gurobi/default.nix b/pkgs/applications/science/math/gurobi/default.nix
index be14d1411285..ee9bdcc6f1b0 100644
--- a/pkgs/applications/science/math/gurobi/default.nix
+++ b/pkgs/applications/science/math/gurobi/default.nix
@@ -1,8 +1,10 @@
-{ stdenv, fetchurl, autoPatchelfHook, python }:
+{ stdenv, lib, fetchurl, autoPatchelfHook, python }:
 
-stdenv.mkDerivation rec {
+let
+  majorVersion = "8.1";
+in stdenv.mkDerivation rec {
   name = "gurobi-${version}";
-  version = "8.1.0";
+  version = "${majorVersion}.0";
 
   src = with stdenv.lib; fetchurl {
     url = "http://packages.gurobi.com/${versions.majorMinor version}/gurobi${version}_linux64.tar.gz";
@@ -44,6 +46,8 @@ stdenv.mkDerivation rec {
     ln -s $out/lib/gurobi-javadoc.jar $out/share/java/
   '';
 
+  passthru.libSuffix = lib.replaceStrings ["."] [""] majorVersion;
+
   meta = with stdenv.lib; {
     description = "Optimization solver for mathematical programming";
     homepage = https://www.gurobi.com;
diff --git a/pkgs/development/libraries/science/math/osi/default.nix b/pkgs/development/libraries/science/math/osi/default.nix
new file mode 100644
index 000000000000..1cc80e78a100
--- /dev/null
+++ b/pkgs/development/libraries/science/math/osi/default.nix
@@ -0,0 +1,42 @@
+{ stdenv, lib, fetchurl, gfortran, pkgconfig
+, blas, zlib, bzip2
+, withGurobi ? false, gurobi
+, withCplex ? false, cplex }:
+
+stdenv.mkDerivation rec {
+  pname = "osi";
+  version = "0.108.4";
+
+  src = fetchurl {
+    url = "https://www.coin-or.org/download/source/Osi/Osi-${version}.tgz";
+    sha256 = "13bwhdh01g37vp3kjwl9nvij5s5ikh5f7zgrqgwrqfyk35q2x9s5";
+  };
+
+  buildInputs =
+    [ blas zlib bzip2 ]
+    ++ lib.optional withGurobi gurobi
+    ++ lib.optional withCplex cplex;
+  nativeBuildInputs = [ gfortran pkgconfig ];
+  configureFlags =
+    lib.optionals withGurobi [ "--with-gurobi-incdir=${gurobi}/include" "--with-gurobi-lib=-lgurobi${gurobi.libSuffix}" ]
+    ++ lib.optionals withCplex [ "--with-cplex-incdir=${cplex}/cplex/include/ilcplex" "--with-cplex-lib=-lcplex${cplex.libSuffix}" ];
+
+  NIX_LDFLAGS =
+    lib.optional withCplex "-L${cplex}/cplex/bin/${cplex.libArch}";
+
+  # Compile errors 
+  NIX_CFLAGS_COMPILE = [ "-Wno-cast-qual" ];
+  hardeningDisable = [ "format" ];
+
+  enableParallelBuilding = true;
+
+  passthru = { inherit withGurobi withCplex; };
+
+  meta = with stdenv.lib; {
+    description = "An abstract base class to a generic linear programming (LP) solver";
+    homepage = "https://github.com/coin-or/Osi";
+    license = licenses.epl10;
+    platforms = platforms.unix;
+    maintainers = with maintainers; [ abbradar ];
+  };
+}
diff --git a/pkgs/development/python-modules/mlrose/default.nix b/pkgs/development/python-modules/mlrose/default.nix
new file mode 100644
index 000000000000..f7d43115a1b5
--- /dev/null
+++ b/pkgs/development/python-modules/mlrose/default.nix
@@ -0,0 +1,24 @@
+{ stdenv, buildPythonPackage, fetchPypi, scikitlearn }:
+
+buildPythonPackage rec {
+  pname = "mlrose";
+  version = "1.2.0";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0vsvqrf1wbbj8i198rqd87hf8rlq7fmv8mmibv8f9rhj0w8729p5";
+  };
+
+  propagatedBuildInputs = [ scikitlearn ];
+
+  postPatch = ''
+    sed -i 's,sklearn,scikit-learn,g' setup.py
+  '';
+
+  meta = with stdenv.lib; {
+    description = "Machine Learning, Randomized Optimization and SEarch";
+    homepage    = "https://github.com/gkhayes/mlrose";
+    license     = licenses.bsd3;
+    maintainers = with maintainers; [ abbradar ];
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index fc1d8208ab82..79a31ca1d368 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -22566,6 +22566,8 @@ in
 
   nauty = callPackage ../applications/science/math/nauty {};
 
+  osi = callPackage ../development/libraries/science/math/osi { };
+
   or-tools = callPackage ../development/libraries/science/math/or-tools {
     pythonProtobuf = pythonPackages.protobuf;
   };
@@ -22818,6 +22820,8 @@ in
       else smlnj;
   };
 
+  fast-downward = callPackage ../applications/science/logic/fast-downward { };
+
   twelf = callPackage ../applications/science/logic/twelf {
     smlnj = if stdenv.isDarwin
       then smlnjBootstrap
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 9bef1b877096..5400438d7dc1 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -2242,6 +2242,8 @@ in {
 
   misaka = callPackage ../development/python-modules/misaka {};
 
+  mlrose = callPackage ../development/python-modules/mlrose { };
+
   mt-940 = callPackage ../development/python-modules/mt-940 { };
 
   mwlib = callPackage ../development/python-modules/mwlib { };