How much of rendering you need? Are you providing the shaders yourself? If you only need multi-platform rendering (including Emscripten, and a shader abstracti

How much of rendering you need? Are you providing the shaders yourself? If you only need multi-platform rendering (including Emscripten, and a shader abstraction), have you looked into BGFX, or even Sokol GFX? They provide the bits you need to render. Unity is even using BGFX in its "Tiny" version. Sokol GFX is new but very easy to use. I believe both have Rust bindings if this is important to you.