LimeJS is a HTML5 game framework for building fast, native-experience games for all modern touchscreens and desktop browsers.
As the name suggests, it is a JavaScript based framework developed by DigitalFruit and is built on Closure Library.
Closure is JavaScript library built by Google and provides user interface widgets, an event framework, a packaging and dependency resolution system, tools for DOM manipulation, tools for creating animation effects (including drag and drop) and a lot more.
LimeJS also comes with Box2D physics library for 2D physics simulations.
The documentation for LimeJS are located here.