Velocity
Accelerated JavaScript animation.
UI Router
The de-facto solution to flexible routing with nested views
Signal R
Incredibly simple real-time web for .NET
Scroll Reveal.js
Declarative on-scroll reveal animations.
Scroll Magic
The jQuery plugin for magical scroll interactions.
Testcafe
A Node.js tool to automate end-to-end web testing.
UA Parser
Lightweight JavaScript-based User-Agent string parser. Supports browser & node.js environment. Also available as jQuery plugin.
Remark
A simple, in-browser, markdown-driven slideshow tool.
Nprogress
For slim progress bars like on YouTube, Medium, etc
Jszip
Create, read and edit .zip files with Javascript
Sigma
An open-source lightweight JavaScript graph drawing library
Dom Purify
DOMPurify - a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMPurify works with a secure default, but offers a lot of configurability and hooks. Demo:
Mediaelement
HTML5 <audio> or <video> player with Flash and Silverlight shims that mimics the HTML5 MediaElement API, enabling a consistent UI in all browsers.
Skrollr
Stand-alone parallax scrolling library for mobile (Android + iOS) and desktop. No jQuery. Just plain JavaScript (and some love).
Robotjs
Node.js Desktop Automation.
Bower
A package manager for the web, created at Twitter
RequireJS
A file and module loader for JavaScript