Sass is a meta-language on top of CSS that‘s used to describe the style of a document cleanly and structurally, with more power than flat CSS allows. Sass both provides a simpler, more elegant syntax for CSS and implements various features that are useful for creating manageable stylesheets.
I am a huge fan of SASS (Syntactically Awesome Stylesheets) for styling Rails applications. I have been using it on all of my projects for quite a while now and have developed some great techniques that make it much easier to organize, write, and read stylesheets in an application
Maybe I haven’t been paying close enough attention, but over the past few years an interesting variation of CSS Sprites has been getting a lot of play on large web sites that serve millions of users.
Web performance expert Nicole Sullivan discusses a set of best practices in the creation of supremely fast, visually impactful web sites.