Untrue, I used a port of Box2d (not this port, our own version) to build an "HTML5" game for sony, see link - http://www.youtube.com/watch?v=AicnuLQxHoQ http://

Untrue, I used a port of Box2d (not this port, our own version) to build an "HTML5" game for sony, see link - http://www.youtube.com/watch?v=AicnuLQxHoQ http://www.youtube.com/watch?v=AicnuLQxHoQ Unfortunately the game was taken down due to the Japan situation. Understandable. Under Safari i was able to simulate ~80 live physics objects in a high collision environment at full frame render, bound to the DOM at 60fps on reasonable hardware 6 months ago (safari still has the fastest DOM paint time out there now). Even when using Firefox 3.6 i could manage around 20 dynamic objects. No CSS3 animation, just math and re-paints. Javascript Math is not slow (at all), its generally the DOM/Canvas slowing you down.