SpritePad : With SpritePad you can create your CSS sprites within seconds. Simply drag & drop your images and have them immediately available as one PNG sprite + ...
css.gg : Minimalistic icon library Designed by code, Customizable & Retina-Ready icons — built 100% in pure CSS. Easy integration: Embed, NPM & API
enquire.js : A lightweight, pure JavaScript library for responding to CSS media queries.
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...
Photon : UI toolkit for building desktop apps with Electron.