Vide
Easy as hell jQuery plugin for video backgrounds.
Turn.js
The page flip effect for HTML5
Rot.js
ROguelike Toolkit
Rivets
Declarative data binding facility
Gif.js
JavaScript GIF encoding library
Alertify.js
JavaScript Alert/Notification System
Swig
Take a swig of the best template engine for JavaScript.
Mavo
Create web applications entirely by writing HTML and CSS!
Alloy Ui
Alloy is a UI metaframework that provides a consistent and simple API for building web applications across allthree levels of the browser: structure, style and behavior.
Spectrum
The No Hassle JavaScript Colorpicker
jScrollPane
Pretty, customisable, cross browser replacement scrollbars
Vorlonjs
A new, open source, extensible, platform-agnostic tool for remotely debugging and testing your JavaScript. Powered by node.js and socket.io
Bootstrap Wysiwyg
Tiny bootstrap-compatible WISWYG rich text editor
Layzr.js
A small, fast, modern, and dependency-free library for lazy loading.
jQuery.maskedinput
jQuery Masked Input Plugin
Es6 Shim
ECMAScript 6 (Harmony) compatibility shims for legacy JavaScript engines
Stacktrace.js
Framework-agnostic, micro-library for getting stack traces in all web browsers