Compass CSS Authoring
Compass uses Sass to make your CSS code resuable and more easily maintained.
There has been a sudden growth around CSS in recent years with frameworks and pre-processors appearing all over the place. Many web developers and designers are now using Compass with Sass as the basis for their CSS production, many finding that it saves them time over their more traditional methods of the past.
It is quite possible, probable in fact, that future versions of CSS will have many of these elements built-in, but for now it is worth trying out the likes of Sass and LESS to see what best suits your work patterns.
The combination of Sass and Compass offer the best features with regards maintaining and updating sitewide css, and having used LESS too, i now will stick with the former as my preferred setup when starting new projects. It is also becoming clear that LESS is slighly less popular across the market as a whole, judging by which appear most frequently in job specs.