Backbone.js
Backbone supplies structure to JavaScript-heavy applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing application over a RESTful JSON interface. The project is hosted on GitHub, and the annotated source code is available, as well as an online test suite, an example application and a list of tutorials. You can report bugs and discuss features on the GitHub issues page, on Freenode IRC in the #documentcloud channel, post questions to the Google Group, or send tweets to @documentcloud.
Backbone is an open-source component of DocumentCloud. http://documentcloud.github.com/backbone/
