diff --git a/pkgs/development/tools/elkhound/default.nix b/pkgs/development/tools/elkhound/default.nix
new file mode 100644
index 000000000000..5c29b10a6139
--- /dev/null
+++ b/pkgs/development/tools/elkhound/default.nix
@@ -0,0 +1,50 @@
+{ stdenv
+, lib
+, fetchFromGitHub
+, bison
+, cmake
+, flex
+, perl
+}:
+
+stdenv.mkDerivation rec {
+  pname = "elkhound";
+  version = "unstable-2020-04-13";
+
+  src = fetchFromGitHub {
+    owner = "WeiDUorg";
+    repo = pname;
+    rev = "a7eb4bb2151c00cc080613a770d37560f62a285c";
+    sha256 = "sha256-Y96OFpBNrD3vrKoEZ4KdJuI1Q4RmYANsu7H3ZzfaA6g=";
+  };
+
+  postPatch = ''
+    patchShebangs scripts
+  '';
+
+  sourceRoot = "source/src";
+
+  nativeBuildInputs = [ bison cmake flex perl ];
+
+  installPhase = ''
+    runHook preInstall
+
+    install -Dm555 -t $out/bin ast/astgen elkhound/elkhound
+    for d in ast elkhound smbase; do
+      install -Dm444 -t $out/lib $d/*.a
+      install -Dm444 -t $out/include/$d $src/src/$d/*.h
+    done
+    install -Dm444 -t $out/share/doc/${pname} $src/src/elkhound/*.txt
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "A parser generator which emits GLR parsers, either in OCaml or C++";
+    homepage = "https://scottmcpeak.com/elkhound/";
+    license = licenses.bsd3;
+    maintainers = with maintainers; [ peterhoeg ];
+    # possibly works on Darwin
+    platforms = platforms.linux;
+  };
+}
diff --git a/pkgs/tools/games/weidu/default.nix b/pkgs/tools/games/weidu/default.nix
new file mode 100644
index 000000000000..d325746dc8ca
--- /dev/null
+++ b/pkgs/tools/games/weidu/default.nix
@@ -0,0 +1,65 @@
+{ stdenv
+, lib
+, fetchFromGitHub
+, elkhound
+, ocaml-ng
+, perl
+, which
+}:
+
+let
+  # 1. Needs ocaml >= 4.04 and <= 4.11
+  # 2. ocaml 4.10 defaults to safe (immutable) strings so we need a version with
+  #    that disabled as weidu is strongly dependent on mutable strings
+  ocaml' = ocaml-ng.ocamlPackages_4_10.ocaml.overrideAttrs (old: {
+    configureFlags = old.configureFlags ++ [
+      # https://github.com/WeiDUorg/weidu/issues/197
+      "--disable-force-safe-string"
+    ];
+  });
+
+in
+stdenv.mkDerivation rec {
+  pname = "weidu";
+  version = "247.00";
+
+  src = fetchFromGitHub {
+    owner = "WeiDUorg";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "sha256-vAIIYn0urQnnL82mdfwJtahrS3uWPFferm+0F13TKcw=";
+  };
+
+  postPatch = ''
+    substitute sample.Configuration Configuration \
+      --replace /usr/bin ${lib.makeBinPath [ ocaml' ]} \
+      --replace elkhound ${elkhound}/bin/elkhound
+
+    mkdir -p obj/{.depend,x86_LINUX}
+  '';
+
+  nativeBuildInputs = [ elkhound ocaml' perl which ];
+
+  buildFlags = [ "weidu" "weinstall" "tolower" ];
+
+  installPhase = ''
+    runHook preInstall
+
+    for b in tolower weidu weinstall; do
+      install -Dm555 $b.asm.exe $out/bin/$b
+    done
+
+    install -Dm444 -t $out/share/doc/weidu README* COPYING
+
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "InfinityEngine Modding Engine";
+    homepage = "https://weidu.org";
+    license = licenses.gpl2Only;
+    maintainers = with maintainers; [ peterhoeg ];
+    # should work fine on both Darwin and Windows
+    platforms = platforms.linux;
+  };
+}
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 1020c51ebffd..1eff16c848d4 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -873,6 +873,10 @@ in
     libgamemode32 = pkgsi686Linux.gamemode.lib;
   };
 
+  elkhound = callPackage ../development/tools/elkhound { };
+
+  weidu = callPackage ../tools/games/weidu { };
+
   gfshare = callPackage ../tools/security/gfshare { };
 
   gobgp = callPackage ../tools/networking/gobgp { };