Video.js
Universal video embed.
Foundation
The most advanced responsive front-end framework in the world. Quickly create prototypes and production code for sites and apps that work on any kind of device.
Express
Sinatra inspired web development framework for node.js -- insanely fast, flexible, and simple
Pixi.js
Super fast HTML 5 2D rendering engine that uses webGL with canvas fallback
Ember
Ember.js is a JavaScript framework that does all of the heavy lifting that you'd normally have to do by hand. There are tasks that are common to every web app; Ember.js does those things for you, so you can focus on building killer features and UI.
Code Mirror
In-browser code editor
Axios
Promise based HTTP client for the browser and node.js
Ace
Ajax.org Cloud9 Editor
Select2
Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.
Underscore
JavaScript's utility _ belt
Backbone
Give your JS App some Backbone with Models, Views, Collections, and Events
Sentry
Sentry is a realtime error logging and aggregation platform
Lodash
An alternative to Underscore.js, delivering consistency, customization, performance, and extra features.
Reveal.js
The HTML Presentation Framework
Modernizr
Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.
Animate.css
Cross-browser CSS3 animations. Plug and play. Do a little dance.
Meteor
Meteor, an ultra-simple, database-everywhere, data-on-the-wire, pure-Javascript web framework.