we just released the first version of the CopperLicht JavaScript 3D engine. It uses WebGL and has a lot of unique features compared to other existing webgl libaries, like a complete world editor. It's free to be used.

It's also quite fast (I personally was surprised how fast WebGL is, congratulations!), there are a few demos on the website here: http://www.ambiera.com/copperlicht/demos.html, one of the demos renders a huge Quake 3 map in playable speed.

This is the first release, and any comments, suggestions and feature requests are welcome.
(Preferably do this in the CopperLicht forums, but I'll try to check this board from time to time anyway.)