Sass (Syntactically Awesome StyleSheets) is a pre-processor for Cascading Style Sheets allowing CSS to be created in a more powerful and developer-friendly way than the normal CSS syntax, then compiled into regular CSS. The Sass syntax supports enhanced functionality such as nested styles and programming-language-style constructs such as variables and calculations. Sass is implemented in Ruby and has been built into a number of programs aimed at Web developers, both commercial and free/open-source.
There are two different syntaxes of Sass:
- The original "nested" syntax, using indentation (rather than brackets) to show nesting levels (somewhat like Python) and newlines instead of semicolons to separate properties. This has an .sass extension.
- The newer SCSS (Sassy CSS) syntax, which is based on CSS3 and designed so that a valid CSS3 file is also a valid SCSS file, but a number of extensions are supported. This has an .scss extension.
The current Sass release as of this writing is known as Maptastic Maple (3.3.4).