Whizdom
Powerful html5 & javascript library for creating applications & games.
...It's intended to use with the newer versions of the most popular browsers, and doesn't depend on any other framework.
It comes in two flavors, a debugging version that provides type checking on native properties and methods, and a release version designed to run at optimal speeds.
Supports: IE 9+, Chrome 7+, Safari 5.1+, Opera 12+, Firefox 4+