Open Source Cube 2: Sauerbraten Engine Running in Browser Using WebGL

BananaBread is a 3D first person shooter that runs on the web. It is a port of Cube 2: Sauerbraten engine, which is written in C++ and OpenGL.

BananaBread is compiled into JavaScript and WebGL using Emscripten so that it can run in modern browsers using standards-based web APIs and without the need for plugins. The project is backed by Mozilla and it is being promoted with Firefox 15, which was released couple of days back.

You can try BananaBread demo from here (Firefox 15 required).