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...
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
DOMAssistant : The modular lightweight JavaScript library, with CSS selectors, event handling, AJAX and complete Unicode support
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
jQuery Masonry : A dynamic layout plugin for jQuery
The flip-side of CSS floats
DropzoneJS is an open source library that provides drag'n'drop file uploads with image previews.