Besides the recent talk about using Gallium3D's LLVMpipe for Mozilla Firefox
, there's another interesting technical discussion happening now about using Mesa on the web to emulate the full OpenGL API using the WebGL API.
The developers working on this so far have been able to implement a portion of the OpenGL ES 2.0 API and then brought the es2gears demo to the web
. WebGL effectively provides a sub-set of OpenGL ES 2.0 functionality so right now that much isn't a huge challenge.
The discussion about the possibilities for Mesa and Emscripten can be explored further via this mailing list thread
, but at the moment there isn't any definitive outcome.