I prefer LESS http://lesscss.org/ http://lesscss.org/ because it does something SASS doesn't, it simply extends CSS with new features using the existing syntax

I prefer LESS http://lesscss.org/ http://lesscss.org/ because it does something SASS doesn't, it simply extends CSS with new features using the existing syntax allowing you to use it on your existing code without having to rewrite everything into someone else's idea of a simpler syntax. It's much simpler to tell your designer "here, now you have x new features" than it is to tell them they have to learn an entirely new syntax and "on by the way, you need to rewrite all your existing CSS to use this."