Box2DJs: a 2D Javascript Physics Engine
Box2Djs is a Javsacript port of the Actionscript port of the C++ 2D Physics Engine Box2D. It was ported form the action script using a automated script, so it shares the exact same api as the flash version.
The example uses the prototype.js javascript library along with Canvas to draw objects, but the engine itself doesn’t care about how the elements are rendered on the screen – people have used Canvs, DOM and SVG in other cases.