I don’t hear many people talking about Sass, but it is indeed fantastic. Basically, Sass is kind of like the Smarty of CSS Templating. Sass files compile to CSS after every change just like Smarty’s TPL files compile directly to PHP. Sass fits well into the Rails don’t-repeat-yourself methodology because you can define color and style constants within CSS rather than explicitly specifying them twenty times. The beauty of Sass is that you get a level of abstraction without any runtime overhead. As a result, Sass performs well and allows quick updates to color schemes and typography without resorting to perl/find or ninja text editor foo. So, why aren’t more people using it?