AngularJS lets you write client-side web applications as if you had a smarter browser. It lets use good old HTML (or HAML, Jade and friends!) as your template language and lets you extend HTML’s syntax to express your application’s components clearly and succinctly
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.
Give your JS App some Backbone with Models, Views, Collections, and Events
Advanced HTML5 Mobile App Framework. A beautiful front-end framework for developing hybrid mobile apps in HTML5. Best friends with AngularJS.
The HTML Presentation Framework
Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.
The streaming build system
Simple HTML5 Charts using the <canvas> tag
Ajax.org Cloud9 Editor
Async utilities for node and the browser