D3Wasm

D3wasm is an experiment to port the id Tech 4 engine (aka. “Doom 3 Engine”) to Emscripten / WebAssembly and WebGL, allowing to run games such as Doom 3 inside modern Web Browsers.

D3Wasm uses emscripten to port the "Doom 3 engine". This is quite notable, as it proves that WebAssembly can bring these large C/C++ codebases using Emscripten to the web, to run impressive 3d games. The d3wasm blog post goes deep into detail on how the project works.

If you are interested in porting C/C++ libraries or applications, I'd highly reccomend Ben Smith's (binji) SFHTML5 Talk on porting C projects to the web. This talk is unrealted to D3Wasm, but can help drive what goes into porting these types of applications.