diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d9000ab..567ed09 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -49,6 +49,52 @@ jobs:
 
       - name: (Zig) Build Shaders
         run: zig build shaders
+      - name: (Zig) Running Test
+        if: runner.os != 'Windows'
+        run: zig build test -DzigCC
+      - name: (Zig) Build Native
+        run: zig build -Dimgui --summary all
+      # - name: (Zig + emsdk) Build Wasm
+      #   run: zig build -Dimgui -DzigCC --summary all -Dtarget=wasm32-emscripten-none -Doptimize=ReleaseSmall
+
+  opend:
+    strategy:
+      fail-fast: false
+      matrix:
+        runs-on: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.runs-on }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: mlugg/setup-zig@v1
+        with:
+          version: master
+      - name: Install opend
+        run: |
+          if [ "$RUNNER_OS" == "Linux" ]; then
+            if [ "$RUNNER_ARCH" == "X64" ]; then
+              curl -sLO https://github.com/opendlang/opend/releases/download/CI/opend-latest-linux-x86_64.tar.xz
+              tar -xf opend-latest-linux-x86_64.tar.xz
+              echo "$PWD/opend-latest-linux-x86_64/bin" >> $GITHUB_PATH
+              $PWD/opend-latest-linux-x86_64/bin/opend install xpack-emscripten
+            fi
+          elif [ "$RUNNER_OS" == "macOS" ]; then
+            if [ "$RUNNER_ARCH" == "ARM64" ]; then
+              curl -sLO https://github.com/opendlang/opend/releases/download/CI/opend-latest-osx-arm64.tar.xz
+              tar -xf opend-latest-osx-arm64.tar.xz
+              echo "$PWD/opend-latest-osx-arm64/bin" >> $GITHUB_PATH
+              $PWD/opend-latest-osx-arm64/bin/opend install xpack-emscripten
+            fi
+          fi
+
+      - name: prepare-linux
+        if: runner.os == 'Linux'
+        run: |
+            sudo apt-get update
+            sudo apt-get install libglu1-mesa-dev mesa-common-dev xorg-dev libasound-dev
+
+      - name: (Zig) Build Shaders
+        run: zig build shaders
+
       - name: (Zig) Running Test
         if: runner.os != 'Windows'
         run: zig build test -DzigCC
diff --git a/build.zig b/build.zig
index d6d144a..74a1673 100644
--- a/build.zig
+++ b/build.zig
@@ -274,7 +274,8 @@ pub fn build(b: *Build) !void {
                 .betterC = if (std.mem.eql(u8, example, "user-data")) false else enable_betterC,
                 .dflags = &.{
                     "-w",
-                    "-preview=all",
+                    "-preview=rvaluerefparam",
+                    "-preview=dip1000",
                 },
                 // fixme: https://github.com/kassane/sokol-d/issues/1 - betterC works on darwin
                 .zig_cc = if (target.result.isDarwin() and !enable_betterC) false else enable_zigcc,
@@ -456,6 +457,7 @@ pub fn ldcBuildStep(b: *Build, options: DCompileStep) !*std.Build.Step.InstallDi
                 \\
                 \\ extern (C):
                 \\
+                \\ version(D_BetterC):
                 \\ version (Emscripten)
                 \\ {
                 \\     union fpos_t
@@ -653,8 +655,9 @@ pub fn ldcBuildStep(b: *Build, options: DCompileStep) !*std.Build.Step.InstallDi
             .emsdk = options.emsdk.?,
             .use_webgpu = backend == .wgpu,
             .use_webgl2 = backend != .wgpu,
-            .use_emmalloc = true,
+            .use_emmalloc = options.betterC,
             .use_filesystem = false,
+            .use_drt = !options.betterC and options.target.result.isWasm(),
             .use_ubsan = options.artifact.?.root_module.sanitize_c orelse false,
             .release_use_lto = options.artifact.?.want_lto orelse false,
             .shell_file_path = b.path("src/sokol/web/shell.html"),
@@ -816,6 +819,7 @@ pub const EmLinkOptions = struct {
     use_emmalloc: bool = false,
     use_filesystem: bool = true,
     use_ubsan: bool = false,
+    use_drt: bool = false,
     shell_file_path: ?Build.LazyPath,
     extra_args: []const []const u8 = &.{},
 };
@@ -866,6 +870,11 @@ pub fn emLinkStep(b: *Build, options: EmLinkOptions) !*Build.Step.InstallDir {
         emcc.addArg(arg);
     }
 
+    if (options.use_drt) {
+        const xpack = b.dependency("xpack", .{}).path("lib").getPath(b);
+        emcc.addFileArg(path(b, b.fmt("{s}/libdruntime-ldc.a", .{xpack})));
+        emcc.addFileArg(path(b, b.fmt("{s}/libphobos2-ldc.a", .{xpack})));
+    }
     // add the main lib, and then scan for library dependencies and add those too
     emcc.addArtifactArg(options.lib_main);
     for (options.lib_main.getCompileDependencies(false)) |item| {
diff --git a/build.zig.zon b/build.zig.zon
index 617402b..55838ab 100644
--- a/build.zig.zon
+++ b/build.zig.zon
@@ -23,5 +23,9 @@
             .url = "git+https://github.com/floooh/sokol-tools-bin#d80b1d8f20fef813092ba37f26723d3880839651",
             .hash = "1220f2ae16952843dd25b6bc86b888a3fd8c3f25d34adddfd8d1d2b9f801429e80e4",
         },
+        .xpack = .{
+            .url = "https://github.com/opendlang/opend/releases/download/CI/opend-latest-xpack-emscripten.tar.xz",
+            .hash = "1220132c994d2f9754174c5fe934413f3fc79603d1a180429bb231aaed6110429cc6",
+        },
     },
 }
diff --git a/src/examples/cube.d b/src/examples/cube.d
index afea8c9..6ba2243 100644
--- a/src/examples/cube.d
+++ b/src/examples/cube.d
@@ -17,142 +17,160 @@ import shd = examples.shaders.cube;
 extern (C):
 @safe:
 
-struct State
+interface ICubeRenderer
 {
-    float rx = 0;
-    float ry = 0;
-
-    sg.Pipeline pip;
-    sg.Bindings bind;
-    sg.PassAction passAction = {
-        colors: [
-            {
-                load_action: sg.LoadAction.Clear,
-                clear_value: {r: 0.25, g: 0.5, b: 0.75, a: 1.0}
-            }
-        ]
-    };
+    void init();
+    void frame();
+    void cleanup();
+}
 
-    Mat4 view()
+class CubeRenderer : ICubeRenderer
+{
+    private struct State
+    {
+        float rx = 0;
+        float ry = 0;
+        sg.Pipeline pip;
+        sg.Bindings bind;
+        sg.PassAction passAction = {
+            colors: [
+                {
+                    load_action: sg.LoadAction.Clear,
+                    clear_value: {r: 0.25, g: 0.5, b: 0.75, a: 1.0}
+                }
+            ]
+        };
+    }
+
+    private State state;
+
+    private Mat4 view()
     {
         return Mat4.lookAt(Vec3(0.0, 1.5, 6.0), Vec3.zero(), Vec3.up());
     }
-}
 
-static State state;
+    private Mat4 computeMvp(float rx, float ry)
+    {
+        immutable proj = Mat4.perspective(60.0, app.widthf() / app.heightf(), 0.01, 10.0);
+        immutable rxm = Mat4.rotate(rx, Vec3(1.0, 0.0, 0.0));
+        immutable rym = Mat4.rotate(ry, Vec3(0.0, 1.0, 0.0));
+        immutable model = Mat4.mul(rxm, rym);
+        immutable view_proj = Mat4.mul(proj, view());
+        return Mat4.mul(view_proj, model);
+    }
 
-void init()
-{
-    sg.Desc gfxd = {environment: sglue.environment,
-    logger: {func: &log.func}};
-    sg.setup(gfxd);
-
-    float[168] vertices = [
-        -1.0, -1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
-        1.0, -1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
-        1.0, 1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
-        -1.0, 1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
-
-        -1.0, -1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
-        1.0, -1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
-        1.0, 1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
-        -1.0, 1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
-
-        -1.0, -1.0, -1.0, 0.0, 0.0, 1.0, 1.0,
-        -1.0, 1.0, -1.0, 0.0, 0.0, 1.0, 1.0,
-        -1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 1.0,
-        -1.0, -1.0, 1.0, 0.0, 0.0, 1.0, 1.0,
-
-        1.0, -1.0, -1.0, 1.0, 0.5, 0.0, 1.0,
-        1.0, 1.0, -1.0, 1.0, 0.5, 0.0, 1.0,
-        1.0, 1.0, 1.0, 1.0, 0.5, 0.0, 1.0,
-        1.0, -1.0, 1.0, 1.0, 0.5, 0.0, 1.0,
-
-        -1.0, -1.0, -1.0, 0.0, 0.5, 1.0, 1.0,
-        -1.0, -1.0, 1.0, 0.0, 0.5, 1.0, 1.0,
-        1.0, -1.0, 1.0, 0.0, 0.5, 1.0, 1.0,
-        1.0, -1.0, -1.0, 0.0, 0.5, 1.0, 1.0,
-
-        -1.0, 1.0, -1.0, 1.0, 0.0, 0.5, 1.0,
-        -1.0, 1.0, 1.0, 1.0, 0.0, 0.5, 1.0,
-        1.0, 1.0, 1.0, 1.0, 0.0, 0.5, 1.0,
-        1.0, 1.0, -1.0, 1.0, 0.0, 0.5, 1.0
-    ];
-    sg.BufferDesc vbufd = {data: {ptr: vertices.ptr, size: vertices.sizeof},};
-    state.bind.vertex_buffers[0] = sg.makeBuffer(vbufd);
-
-    ushort[36] indices = [
-        0, 1, 2, 0, 2, 3,
-        6, 5, 4, 7, 6, 4,
-        8, 9, 10, 8, 10, 11,
-        14, 13, 12, 15, 14, 12,
-        16, 17, 18, 16, 18, 19,
-        22, 21, 20, 23, 22, 20,
-    ];
-    sg.BufferDesc ibufd = {
-        type: sg.BufferType.Indexbuffer,
-        data: {ptr: indices.ptr, size: indices.sizeof},
-    };
-    state.bind.index_buffer = sg.makeBuffer(ibufd);
-
-    sg.PipelineDesc pld = {
-        layout: {
-            attrs: [
-                shd.ATTR_CUBE_POSITION: {format: sg.VertexFormat.Float3},
-                shd.ATTR_CUBE_COLOR0: {format: sg.VertexFormat.Float4},
-            ],
-        },
-        shader: sg.makeShader(shd.cubeShaderDesc(sg.queryBackend())),
-        index_type: sg.IndexType.Uint16,
-        cull_mode: sg.CullMode.Back,
-        depth: {write_enabled: true,
-        compare: sg.CompareFunc.Less_equal},
-    };
-    state.pip = sg.makePipeline(pld);
-}
+    void init()
+    {
+        sg.Desc gfxd = {
+            environment: sglue.environment,
+            logger: {func: &log.func}
+        };
+        sg.setup(gfxd);
+
+        float[168] vertices = [
+            -1.0, -1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
+            1.0, -1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
+            1.0, 1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
+            -1.0, 1.0, -1.0, 1.0, 0.0, 0.0, 1.0,
+
+            -1.0, -1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
+            1.0, -1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
+            1.0, 1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
+            -1.0, 1.0, 1.0, 0.0, 1.0, 0.0, 1.0,
+
+            -1.0, -1.0, -1.0, 0.0, 0.0, 1.0, 1.0,
+            -1.0, 1.0, -1.0, 0.0, 0.0, 1.0, 1.0,
+            -1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 1.0,
+            -1.0, -1.0, 1.0, 0.0, 0.0, 1.0, 1.0,
+
+            1.0, -1.0, -1.0, 1.0, 0.5, 0.0, 1.0,
+            1.0, 1.0, -1.0, 1.0, 0.5, 0.0, 1.0,
+            1.0, 1.0, 1.0, 1.0, 0.5, 0.0, 1.0,
+            1.0, -1.0, 1.0, 1.0, 0.5, 0.0, 1.0,
+
+            -1.0, -1.0, -1.0, 0.0, 0.5, 1.0, 1.0,
+            -1.0, -1.0, 1.0, 0.0, 0.5, 1.0, 1.0,
+            1.0, -1.0, 1.0, 0.0, 0.5, 1.0, 1.0,
+            1.0, -1.0, -1.0, 0.0, 0.5, 1.0, 1.0,
+
+            -1.0, 1.0, -1.0, 1.0, 0.0, 0.5, 1.0,
+            -1.0, 1.0, 1.0, 1.0, 0.0, 0.5, 1.0,
+            1.0, 1.0, 1.0, 1.0, 0.0, 0.5, 1.0,
+            1.0, 1.0, -1.0, 1.0, 0.0, 0.5, 1.0
+        ];
+        sg.BufferDesc vbufd = {
+            data: {ptr: vertices.ptr, size: vertices.sizeof},
+        };
+        state.bind.vertex_buffers[0] = sg.makeBuffer(vbufd);
+
+        ushort[36] indices = [
+            0, 1, 2, 0, 2, 3,
+            6, 5, 4, 7, 6, 4,
+            8, 9, 10, 8, 10, 11,
+            14, 13, 12, 15, 14, 12,
+            16, 17, 18, 16, 18, 19,
+            22, 21, 20, 23, 22, 20,
+        ];
+        sg.BufferDesc ibufd = {
+            type: sg.BufferType.Indexbuffer,
+            data: {ptr: indices.ptr, size: indices.sizeof},
+        };
+        state.bind.index_buffer = sg.makeBuffer(ibufd);
+
+        sg.PipelineDesc pld = {
+            layout: {
+                attrs: [
+                    shd.ATTR_CUBE_POSITION: {format: sg.VertexFormat.Float3},
+                    shd.ATTR_CUBE_COLOR0: {format: sg.VertexFormat.Float4},
+                ],
+            },
+            shader: sg.makeShader(shd.cubeShaderDesc(sg.queryBackend())),
+            index_type: sg.IndexType.Uint16,
+            cull_mode: sg.CullMode.Back,
+            depth: {write_enabled: true,
+            compare: sg.CompareFunc.Less_equal},
+        };
+        state.pip = sg.makePipeline(pld);
+    }
 
-void frame()
-{
-    immutable float t = cast(float)(app.frameDuration() * 60.0);
-
-    state.rx += 1.0 * t;
-    state.ry += 2.0 * t;
-
-    shd.VsParams vsParams = {mvp: computeMvp(state.rx, state.ry)};
-
-    sg.Pass pass = {action: state.passAction, swapchain: sglue.swapchain()};
-    sg.beginPass(pass);
-    sg.applyPipeline(state.pip);
-    sg.applyBindings(state.bind);
-    sg.Range r = {ptr: &vsParams, size: vsParams.sizeof};
-    sg.applyUniforms(shd.UB_VS_PARAMS, r);
-    sg.draw(0, 36, 1);
-    sg.endPass();
-    sg.commit();
-}
+    void frame() @trusted
+    {
+        immutable float t = cast(float)(app.frameDuration() * 60.0);
+
+        state.rx += 1.0 * t;
+        state.ry += 2.0 * t;
+
+        shd.VsParams vsParams = {mvp: computeMvp(state.rx, state.ry)};
+
+        sg.Pass pass = {action: state.passAction, swapchain: sglue.swapchain()};
+        sg.beginPass(pass);
+        sg.applyPipeline(state.pip);
+        sg.applyBindings(state.bind);
+        sg.Range r = {ptr: &vsParams, size: vsParams.sizeof};
+        sg.applyUniforms(shd.UB_VS_PARAMS, r);
+        sg.draw(0, 36, 1);
+        sg.endPass();
+        sg.commit();
+    }
 
-void cleanup()
-{
-    sg.shutdown();
+    void cleanup()
+    {
+        sg.shutdown();
+    }
 }
 
-Mat4 computeMvp(float rx, float ry)
-{
-    immutable proj = Mat4.perspective(60.0, app.widthf() / app.heightf(), 0.01, 10.0);
-    immutable rxm = Mat4.rotate(rx, Vec3(1.0, 0.0, 0.0));
-    immutable rym = Mat4.rotate(ry, Vec3(0.0, 1.0, 0.0));
-    immutable model = Mat4.mul(rxm, rym);
-    immutable view_proj = Mat4.mul(proj, state.view());
-    return Mat4.mul(view_proj, model);
-}
+private __gshared ICubeRenderer renderer;
 
-void main()
+void main() @system
 {
+    renderer = new CubeRenderer();
+
     app.Desc runner = {
         window_title: "cube.d",
-        init_cb: &init,
-        frame_cb: &frame,
-        cleanup_cb: &cleanup,
+
+        init_cb: &initWrapper,
+        frame_cb: &frameWrapper,
+        cleanup_cb: &cleanupWrapper,
         width: 800,
         height: 600,
         sample_count: 4,
@@ -161,3 +179,18 @@ void main()
     };
     app.run(runner);
 }
+
+extern (C) private void initWrapper() @system
+{
+    renderer.init();
+}
+
+extern (C) private void frameWrapper() @system
+{
+    renderer.frame();
+}
+
+extern (C) private void cleanupWrapper() @system
+{
+    renderer.cleanup();
+}
diff --git a/src/examples/mrt.d b/src/examples/mrt.d
index 685c504..a6e018f 100644
--- a/src/examples/mrt.d
+++ b/src/examples/mrt.d
@@ -229,7 +229,7 @@ void init()
     state.dbg.bind.samplers[shd.SMP_SMP] = smp;
 }
 
-void frame()
+void frame() @trusted
 {
     immutable(float) dt = (app.frameDuration() * 60.0);
     state.rx += 1.0 * dt;
diff --git a/src/examples/user_data.d b/src/examples/user_data.d
index 5c90023..75580e7 100644
--- a/src/examples/user_data.d
+++ b/src/examples/user_data.d
@@ -29,9 +29,9 @@ void frame_userdata(scope void* userdata) @trusted
     auto state = cast(ExampleUserData*) userdata;
 
     state.data++;
-    version (WebAssembly)
+    version (D_BetterC)
     {
-        // TODO support
+
     }
     else
     {
@@ -43,18 +43,9 @@ void frame_userdata(scope void* userdata) @trusted
         {
             state.map.clear();
         }
-    }
-    debug
-    {
         import std.stdio : writeln;
 
-        try
-        {
-            writeln(*state);
-        }
-        catch (Exception)
-        {
-        }
+        writeln(*state);
     }
 
     sg.Pass pass = {swapchain: sglue.swapchain};