Among other things, the WHATWG is standardizing Apple's Canvas element which is something web developers have wanted for years: A way to draw graphics inside the browser. Problem is that so far only the 2D part has been documented, even though both Mozilla and Opera are working on 3D support.
Well, to fill the gap I've put up a working software renderer here that uses the 2D commands to draw a simple (but real, not Doom-style 2.5D) 3D model from an OBJ file. It's not perfect and I'm taking a lot of shortcuts to speed up rendering, but it works pretty well. The code is available under GPL so you can take whatever you want and start your own program. The target for mine is to eventually become a racing game, and from what I've seen so far it seems possible to at least get VirtuaRacer style graphics.
Here's the link again: Canvas 3D Demo
Feel free to give feedback"