Tippyjs
Highly customizable vanilla JS tooltip/popover library
Gator
Event delegation in Javascript
Mootools Core
MooTools Core Repository
Zest
An absurdly fast CSS selector engine.
jScrollPane
Pretty, customisable, cross browser replacement scrollbars
Moovie.js
Movie focused HTML5 Player
Voyeur.js
Voyeur is a tiny (1.2kb) Javascript library that lets you traverse and manipulate the DOM the way it should have been.
Turbolinks
Turbolinks makes navigating your web application faster
Prototype
Prototype JavaScript framework
Dragula
:ok_hand: Drag and drop so simple it hurts
Domready
let's you know when the dom is ready
Cyclejs
A functional and reactive JavaScript framework for predictable code
Html
A simple, extensible way to work directly with the DOM.
Gliojs
Exit popup easely. Detects if the mouse of a user leaves the viewport borders of your website
Eqcss
EQCSS is a plugin that introduces Element Queries, Scoped CSS, a Parent selector, and responsive JavaScript to all browsers IE8 and up
Motionia
Motionia is a lightweight simplified on demand animation library! https://git.io/motionia
Ac Colors
ac-colors is a reactive JavaScript color library that can freely convert between RGB, HSL, HEX, XYZ, LAB, LCHab, LUV, and LCHuv, as well as handle random color generation and contrast ratio calculation.