Dc.js
Multi-Dimensional charting built to work natively with crossfilter rendered with d3.js
Zxcvbn
zxcvbn, named after a crappy password, is a JavaScript password strength estimation library. Use it to implement a custom strength bar on a signup form near you!
Loaders.css
Delightful, performance-focused pure css loading animations.
Pickadate.js
lightweight jquery date selector with multi-language support
Nightwatch
UI automated testing framework based on node.js and selenium webdriver
Vivus
JavaScript library to make drawing animation on SVG
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
Wow
Reveal CSS animation as you scroll down a page
Scroll Reveal.js
Declarative on-scroll reveal animations.
Perfect Scrollbar
Tiny but perfect jQuery scrollbar plugin
Sinon.js
Test spies, stubs and mocks for JavaScript.
Hint.css
A tooltip library in CSS for your lovely websites.
Snap.svg
The JavaScript library for modern SVG graphics.
Fuelux
Extends Twitter Bootstrap with additional lightweight JavaScript controls. Easy to install, customize, update, and optimize. All functionality covered by live documentation and unit tests.
Remark
A simple, in-browser, markdown-driven slideshow tool.
Famous
Famo.us is a powerful JavaScript framework designed to build rich, interactive web applications. It is the only framework that provides an open source 3D layout engine fully integrated with a 3D physics-based animation engine that can render to DOM, Canvas, or WebGL. Famo.us is currently in public beta.
Numeral
A javascript library for formatting and manipulating numbers.