Enquire.js
Awesome Media Queries in JavaScript
Xdomain
A pure JavaScript CORS alternative
Unveil
A very lightweight jQuery plugin to lazy load images
Aura
A scalable, event-driven JavaScript architecture for developing widget-based applications. Works with Backbone.js and other frameworks.
Sproutcore
JavaScript Application Framework - JS library only
Nuclear Js
Reactive Flux built with ImmutableJS data structures. Framework agnostic.
Stampit
Create objects from reusable, composable behaviors.
Mdb React Ui Kit
React 17 & Bootstrap 5 & Material Design 2.0 UI KIT
Ink
An HTML5/CSS3 framework used at SAPO for fast and efficient website design and prototyping
Sly
JavaScript library for one-directional scrolling with item based navigation support.
Switchery
iOS 7 style switches for your checkboxes
Flow Type.js
Web typography at its finest: font-size and line-height based on element width.
q Tip2
qTip2 - Pretty powerful tooltips
Isomer
Simple isometric graphics library for HTML5 canvas
Should.js
BDD style assertions for node.js -- test framework agnostic
Jump.js
A small, modern, dependency-free smooth scrolling library.
PhysicsJS
A modular, extendable, and easy-to-use physics engine for javascript