rsvp.js : A lightweight library that provides tools for organizing asynchronous code
SVG Web : SVG Web is a JavaScript library which provides SVG support on many browsers, including Internet Explorer, Firefox, and Safari. Using the library plus ...
howler.js : howler.js is an audio library for the modern web. It defaults to Web Audio API and falls back to HTML5 Audio.
Zepto.js : Zepto is a minimalist JavaScript library for modern browsers with a largely jQuery-compatible API. If you use jQuery, you already know how to use Zept...
Headroom.js : Headroom.js is a lightweight, high-performance JS widget (with no dependencies!) that allows you to react to the user's scroll.
Rainbow is a code syntax highlighting library written in Javascript.
It was designed to be lightweight (1.4kb), easy to use, and extendable.
It is completely themable via CSS.