LESS
LESS extends CSS with dynamic behavior such as variables, mixins, operations and functions. LESS runs on both the client-side (IE 6+, Webkit, Firefox) and server-side, with Node.js.
CSS
Cascading Style Sheets (CSS) is a simple mechanism for adding style (e.g., fonts, colors, spacing) to web documents.
Sass
Sass is a stylesheet language initially designed by Hampton Catlin and developed by Nathan Weizenbaum. After its initial versi ...
PostCSS
A tool for transforming CSS with JavaScript
Stylus
Stylus is a revolutionary new language, providing an efficient, dynamic, and expressive way to generate CSS. Supporting both a ...