Here's a full game engine written in C++ ported over to HTML5, WebGL.
Mozilla Ports Full FPS Engine to WebGL; Playable Demo : Read more
Mozilla Ports Full FPS Engine to WebGL; Playable Demo : Read more
Nvidia: requires driver numbered 8.17.12.5721 or greater
AMD: requires driver numbered 8.741.0.0 or greater
Intel: requires driver number 6.14.11 on XP, 7.15.10 on Vista, and 8.15.10 on Windows 7