A 1:1 javascript port of the 3D physics engine "qu3e" for use in browsers. Here's a demo:

I did this for a 3D game I'm developing that I'd like to port to JS, so that it's playable in browsers (and supported on many devices).
I needed physics to be synchronized across all clients, and also be fast enough to run on an iPhone, and what better way to do that than with the same engine.

A full demo is included. Render/debug functions are ported but are N/A (and so is file dumping). I just plug it straight into WebGL.

All credits to Randy Gaul