Sinon.js
Test spies, stubs and mocks for JavaScript.
Mask Js
Zen Coding | Markup | Template | HMVC
jQuery hotkeys
jquery.hotkeys plugin lets you easily add and remove handlers for keyboard events anywhere in your code supporting almost any key combination. It takes one line of code to bind/unbind a hot key combination
Easy Pie Chart
Lightweight jQuery plugin to render simple, animated and retina ready pie charts with the HTML5 canvas element
Backbone localStorage
A localStorage adapter for Backbone.js
Timeline JS
TimelineJS: A Storytelling Timeline built in JavaScript.
D3 Cloud
Create word clouds in JavaScript.
Mixitup
A CSS3 and jQuery Filter & Sort Plugin
jTypes
jTypes is the most comprehensive and robust JavaScript library for overcoming differential inheritance with prototype-based objects. Its lightweight yet powerful design provides web programmers on any platform or browser the ability to emulate classical inheritance where objects are defined by classes.
Poly
Small, fast, awesome. The only ES5-ish set of polyfills (shims) you can mix-and-match because they're individual AMD modules.
Rest
RESTful HTTP client for JavaScript
Meld
AOP for JS with before, around, on, afterReturning, afterThrowing, after advice, and pointcuts
Cram
Simple AMD and CommonJS module bundler.
Two.js
A renderer agnostic two-dimensional drawing api for the web.
Dataset
JavaScript library that makes managing the data behind client-side visualisations easy
Elastislide
Elastislide is a responsive image carousel that will adapt fluidly in a layout. It is a jQuery plugin that can be laid out horizontally or vertically with a pre-defined minimum number of shown images
Boiler
Boiler is a utility library that makes every day tasks in JavaScript easier by providing over 115 methods that work on arrays, collections, functions, numbers, objects, and strings.