CSS is necessary in order to specify how fonts, colors, images and layout properties look and act. You need CSS to make your site look "good", but why write plain CSS when you can write Sassy CSS? In a world of CSS3 and browser-specific implementations, writing standard CSS can get tedious. Meet the new CSS, Compass, Sass, and Susy.

Sass and SCSS (Sassy CSS) are CSS syntaxes that will change your styling' life. Both compile to CSS, and both make writing CSS3 the best ever. Compass is a super-powered framework to save you time and works with both syntaxes. Behold the power of CSS3 mixins, CSS resets, typography shortcuts and helper functions in a single line! The final pièce de résistance is Susy, a flexible grid option for people who like grids, including flexible responsive and adaptive options.

Introduce yourself to these three Ruby gems and never write vanilla CSS again.

http://sass-lang.com
http://compass-style.org
http://susy.oddbird.net

Slides: 

CSS - CompassSassSusy.pdf