Ladda
Buttons with built-in loading indicators.
Gifplayer
Customizable jquery plugin to play and stop animated gifs. Similar to 9gag's. Support for video formats
Pico Modal
A small, self-contained JavaScript modal library
Angular Strap
AngularJS 1.2+ native directives for Bootstrap 3.
Bootstrap Tour
Quick and easy product tours with Twitter Bootstrap Popovers
Wijmo Open
Open Source jQuery UI widgets
jQuery Autocomplete
Ajax Autocomplete for jQuery allows you to easily create autocomplete/autosuggest boxes for text input fields.
Vex
A modern dialog library which is highly configurable and easy to style. #hubspot-open-source
Simptip
A simple CSS tooltip made with Sass
Highlight.js
Javascript syntax highlighter
Jquery.payment
A general purpose library for building credit card forms, validating inputs and formatting numbers.
Mixitup
A CSS3 and jQuery Filter & Sort Plugin
Uptodate
Keep your timestamps up to date
Medium Editor
Medium.com WYSIWYG editor clone.
Tooltipster
A jQuery tooltip plugin
React Table
⚛️ Hooks for building fast and extendable tables and datagrids for React
Progressbar.js
Beautiful and responsive progress bars