Klass
a utility for creating expressive classes in JavaScript
Flippant.js
A mini dependancy-less UI lib for flipping over DOM nodes.
Autolink Js
Tiny little tool to find URLs in a string of text and hyperlink them
Winjs
WinJS project by Microsoft Open Technologies
Sea.js
A Module Loader for the Web
Packery
bin-packing layout library
Immutable Js
Immutable persistent data collections for Javascript which increase efficiency and simplicity.
History.js
History.js gracefully supports the HTML5 History/State APIs (pushState, replaceState, onPopState) in all browsers. Including continued support for data, titles, replaceState. Supports jQuery, MooTools and Prototype. For HTML5 browsers this means that you can modify the URL directly, without needing to use hashes anymore. For HTML4 browsers it will revert back to using the old onhashchange functionality.
Fast Check
Property based testing framework for JavaScript (like QuickCheck) written in TypeScript
Bootstrap Daterangepicker
Date range picker component for Bootstrap
Velocity
Accelerated JavaScript animation.
Zenscroll
A JavaScript module to smooth-scroll web pages and other scrollable elements
Notie.js
A clean and simple notification plugin (alert/growl style) for javascript, with no dependencies.
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.
Montage
Core framework: Montage simplifies the development of rich HTML5 applications by providing modular components, real-time two-way data binding, CommonJS dependency management, and many more conveniences. Join us on irc.freenode.net#montage or https://groups.google.com/d/forum/montagejs
Stacktrace.js
Framework-agnostic, micro-library for getting stack traces in all web browsers
Grunt
Grunt: The JavaScript Task Runner