Compass: A Powerful Stylesheet Framework
Compass is a stylesheet framework (and not only a collection of classes) for Ruby.
Using Compass, you can still use the other css frameworks -blueprint, yui, 960- that are ported to Sass and they are ready to be used in your ruby-based web application or stand-alone via a simple command-line interface.
The framework comes with a detailed documentation on:
You can also watch the podcast on how Compass works.