Impact.js
A low-cost, commercial HTML5 games engine.
Impact.js is one of the few available commercial HTML5 Game Engines, but don’t let that scare you off – at $99 per seat with no royalties Impact won’t break the bank. As one would expect from a commercial engine, Impact.js is well documented with an active forum where users can go to find answers and ask questions, with many of the questions answered by the Author himself.
One of the unique features of Impact.js is that there is an iOS compatibility layer that allows you to package your Game to be put in the iOS App store and have the graphics rendered in native OpenGL.