Product Comparisons - Compare any 2 software products
CSS Next - Use tomorrow’s CSS syntax, today.
AlternativeTo - AlternativeTo lets you find apps and software for Windows, Mac, Linux, iPhone, iPad, Android, Android Tablets, Web Apps, Online, Windows Tablets and more by recommending alternatives to apps you already know.
Garden (Clojure) - Unlike the mini-languages that are other pre/post-processor options, Garden leverages the full power of the Clojure programming language for CSS.
TestBox - Test drive your software options before you buy
Stylus - EXPRESSIVE, DYNAMIC, ROBUST CSS