rsvp.js : A lightweight library that provides tools for organizing asynchronous code
xui.js : A super micro tiny DOM library for authoring HTML5 mobile web applications.
Photon : UI toolkit for building desktop apps with Electron.
Moment.js : A javascript date library for parsing, validating, manipulating, and formatting dates.
Wave.js : Audio visualizer library for javascript. Create dynamic animations that react to an audio file or audio stream.
TogetherJS is a free, open source JavaScript library by Mozilla that adds collaboration features and tools to your website. By adding TogetherJS to your site, your users can help each other out on a website in real time!