Yepnope.js
An Asynchronous Conditional Resource Loader
Kute.js
KUTE.js is a native Javascript animation engine featuring badass performance, morphSVG, drawSVG, 2D and 3D transforms, SVG transforms, colors, as well as other CSS3 properties or presentation attributes.
Medium Editor Insert Plugin
jQuery insert plugin for MediumEditor (Medium.com WYSIWYG editor clone)
Infinity
UITableViews for the web.
Audio.js
A cross-browser javascript wrapper for the html5 audio tag
Mobiscroll
The customizable HTML5 spinner/scroller control for touch devices like smartphones and tablets
Asm Dom
A minimal WebAssembly virtual DOM to build C++ SPA (Single page applications)
String.js
Extra JavaScript string methods.
Web Audio Api
The Web Audio API, developed by the W3C Audio WG
Qooxdoo
A Universal JavaScript Framework
Pencilblue
Full stack online publishing and CMS for Node.js
Jsblocks
Better MV-ish Framework
Batman
Fighting Crime and Kicking Apps
Store
A better way to use localStorage and sessionStorage
Reactable
Fast, flexible, and simple data tables in React
Angular Gantt
A Gantt chart directive for Angular.js without any other dependencies.
Garlic.js
Garlic.js allows you to automatically persist your forms' text and select field values locally, until the form is submitted. This way, your users don't lose any precious data if they accidentally close their tab or browser.