A simple and lightweight mixin library for Sass.
Based on the Sass stylesheet language, Compass is the greatest stylesheet authoring framework in the universe.
The open source, static web server with built-in preprocessing. Sass, LESS, Stylus, CoffeeScript and Markdown
Koala is a GUI application for Less, Sass, Compass and CoffeeScript compilation, to help web developers to use them more efficiently. Koala can run in windows, linux and mac.
Less extends CSS with dynamic behavior such as variables, mixins, operations and functions. Less runs on both the server-side (with Node.js and Rhino) or client-side (modern browsers only).
Myth is a preprocessor that lets you write pure CSS without having to worry about slow browser support, or even slow spec approval. It's like a CSS polyfill.
PostCSS is a tool to transform CSS with JS plugins. Like Sass, but modular and much powerful.
Sass is the most mature, stable, and powerful professional grade CSS extension language in the world.
Scout is a cross-platform app that delivers the power of Sass & Compass into the hands of web designers.
Stylus is an innovative stylesheet language that compiles down to CSS. Inspired by SASS, Stylus is built with node.js.