Closure Tools : The Closure Compiler, Library, Templates, and Stylesheets help developers create powerful and efficient JavaScript.
Draggable : Draggable is a modular drag & drop library, allowing you to start small and build up with the features you need. At its most basic, Draggable gives yo...
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.
dancer.js : dancer.js is a high-level audio API, usable with both Mozilla's Audio Data API and Webkit's Web Audio API with flash fallback, designed to make sweet ...
Web Forms : Web Forms 2.0 Cross-Browser Implementation
Rainbow is a code syntax highlighting library written in Javascript.
It was designed to be lightweight (1.4kb), easy to use, and extendable.
It is completely themable via CSS.