A lot of designers use some sort of CSS pre-processor, whether that be Sass, LESS or Stylus.You’re probably aware that Compass is a framework built on Sass, and although its installation may be off-putting, once you use it you’ll quickly discover it’s one of the best skills any web designer can learn.If you’ve never used Sass before, I’d recommend that you take a look at WDD’s introduction to Sass. Compass works like a framework for your CSS. When you’re working on a large project it’s easy for things to get out of hand and often finding things in your own CSS is a challenge. Compass attempts to address these problems, with the added benefit of working with vendor prefixes.