Anime.js : Anime.js is a fast, multipurpose and lightweight JavaScript animation library with a simple, yet powerful API.
It works with CSS properties, SVG, DOM ...
css.gg : Minimalistic icon library Designed by code, Customizable & Retina-Ready icons — built 100% in pure CSS. Easy integration: Embed, NPM & API
Reset CSS : The goal of a reset stylesheet is to reduce browser inconsistencies in things like default line heights, margins and font sizes of headings, and so on...
enquire.js : A lightweight, pure JavaScript library for responding to CSS media queries.
Sprite Cow : Sprite Cow helps you get the background-position, width and height of sprites within a spritesheet as a nice bit of copyable css.
