JavascriptOO : Every javascript project you should be looking into.
With examples, categories, install commands, CDN links, project and author stats, and more.
script.aculo.us : script.aculo.us provides you with
easy-to-use, cross-browser user
interface JavaScript libraries to make
your web sites and web applications fly.
xui.js : A super micro tiny DOM library for authoring HTML5 mobile web applications.
stream.js : stream.js is a tiny stand-alone Javascript library that unlocks a new data structure for you: streams.
