CSS preprocessors
SASS, LESS, Stylus
http://css-tricks.com/sass-vs-less/ :: SASS vs. LESS | CSS-Tricks http://designshack.net/articles/css/sass-vs-stylus-who-wins-the-minimal-syntax-battle/ :: Sass vs. Stylus: Who Wins the Minimal Syntax Battle? | Design Shack
http://compass-style.org/ :: Compass Home | Compass Documentation
http://learnboost.github.com/stylus/ :: Stylus https://github.com/visionmedia/nib#readme :: visionmedia/nib · GitHub
Arbitrary CSS preprocessing library for node.js https://github.com/visionmedia/rework#readme :: visionmedia/rework