It allows you to write pure CSS code in the style of programming languages;
EASY TO USE
This is a CSS extension with which designers and developers can work much more efficiently and faster;
A LOT OF TOOLS
Sass is compatible with all versions of CSS, you can use any available CSS-libraries;
It can use nesting syntax and such useful functions like color manipulation, mathematical and other meanings.
Sass is a CSS extension that gives power and elegance to this simple language. Sass will give you the ability to use variables, nested rules, mixins, inline imports, and more, all with a fully CSS-compatible syntax. Sass helps keep huge style sheets well organized and make small styles work faster. Sass can be used in three ways: as a command line, as a separate Ruby module, and as a plug-in for a rack framework, including Ruby on Rails and Merb.