Wijmo Open
Open Source jQuery UI widgets
Twitterlib
Twitter JavaScript API library
Rimg
A responsive image solution for browsers that support mediaqueries. Pure javascript and no server-side code.
Onionskin
A client- and server-side multi-layer cache manager library
Lmd
LMD: Lazy Module Declaration. Be lazy: lazy load @ lazy init
Domenu
Customized version of Nestable for WordPress-like back-end hierarchical menu creation.
Black
World's fastest HTML5 2D game engine 🛸
Agile
Agile Css3 Engine
jQuery Autocomplete
Ajax Autocomplete for jQuery allows you to easily create autocomplete/autosuggest boxes for text input fields.
Tiny Slider
Vanilla javascript slider for all purposes.
Tether
A positioning engine to make overlays, tooltips and dropdowns better #hubspot-open-source
Sweetalert2
A beautiful, responsive, highly customizable and accessible (WAI-ARIA) replacement for JavaScript's popup boxes. Zero dependencies.
Plottable
A library of modular chart components, built on D3
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
Messenger
Growl-style alerts and messages for your app. #hubspot-open-source
Joint
JavaScript diagramming library
Impress.js
It's a presentation framework based on the power of CSS3 transforms and transitions in modern browsers and inspired by the idea behind prezi.com.