backbone.js

This looks like a useful tool for those that write a lot of javascript for web development.

From backbone.js website:
"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."

Here is a quick write up on how to use the library from Thomas Davis.