Selectivity
Modular and light-weight selection library for jQuery and Zepto.js
Jasmine
DOM-less simple JavaScript testing framework
JS Xlsx
Javascript XLSX / XLSM / XLSB (Excel 2007+) parser and (one day) writer
Immutable Js
Immutable persistent data collections for Javascript which increase efficiency and simplicity.
ES5 Shims
ECMAScript 5 compatibility shims for legacy JavaScript engines
Bottlejs
A powerful, extensible dependency injection micro container for JavaScript applications
Bookshelf
A simple Node.js ORM for PostgreSQL, MySQL and SQLite3 built on top of Knex.js
Anima
CSS animations with a soul
Pioneer
Integration Testing
Layr
Dramatically simplify full‑stack development
JsRender
A light-weight but powerful templating engine, highly extensible, without DOM or jQuery dependency.
Elevator.js
Finally, a "back to top" button that behaves like a real elevator.
Handorgel
Accessible W3C conform accordion written in ES6.
Flexie
Legacy support for the CSS3 Flexible Box Model
Showdown
JavaScript port of Markdown
Script.js
Asyncronous JavaScript loader and dependency manager
Embed.js
A jQuery plugin that analyses the string and automatically embeds emojis, media, maps, tweets, code and services.