enquire.js : A lightweight, pure JavaScript library for responding to CSS media queries.
Dropzone.js : DropzoneJS is an open source library that provides drag'n'drop file uploads with image previews.
store.js : localStorage wrapper for all browsers without using cookies or flash. Uses localStorage, globalStorage, and userData behavior under the hood.
jQuery Masonry : A dynamic layout plugin for jQuery
The flip-side of CSS floats
