jQuery Masonry : A dynamic layout plugin for jQuery
The flip-side of CSS floats
Dropzone.js : DropzoneJS is an open source library that provides drag'n'drop file uploads with image previews.
RequireJS : RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino ...
hunt : Library to detect when DOM elements become visible and disappear on scroll.
Web Forms : Web Forms 2.0 Cross-Browser Implementation
A simple library for handling keyboard shortcuts in Javascript.