C3
A D3-based reusable chart library
Lowdb
An extendable JSON database for Node and the browser powered by lodash
Bonzo
library agnostic, extensible DOM utility
jQuery Autocomplete
Ajax Autocomplete for jQuery allows you to easily create autocomplete/autosuggest boxes for text input fields.
Velocity
Accelerated JavaScript animation.
Sly
JavaScript library for one-directional scrolling with item based navigation support.
Sails
Realtime MVC Framework for Node.js
Machina.js
js ex machina - finite state machines in JavaScript
History.js
History.js gracefully supports the HTML5 History/State APIs (pushState, replaceState, onPopState) in all browsers. Including continued support for data, titles, replaceState. Supports jQuery, MooTools and Prototype. For HTML5 browsers this means that you can modify the URL directly, without needing to use hashes anymore. For HTML4 browsers it will revert back to using the old onhashchange functionality.
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.
Autosize
jQuery plugin for dynamic textarea sizing
Svg.js
A lightweight library for manipulating and animating SVG
Bootstrap Datepicker
A datepicker for @twitter bootstrap forked from Stefan Petre's (of eyecon.ro), improvements by @eternicode
Tabletop
Tabletop.js gives spreadsheets legs
Slate
A completely customizable framework for building rich text editors.
Remarkable
Markdown parser, done right. Commonmark support, extensions, syntax plugins, high speed - all in one.
Platform.js
A platform detection library that works on nearly all JavaScript platforms.