Susy
Susy is a Sass based framework that lets you use your own markup and design and use their math to make it work.
Related Resources
Bourbon Neat
Neat is an open source fluid grid framework built on top of Sass and Bourbon using em units and golden ratios.
960 Grid System
The 960 Grid System is an effort to streamline web development workflow by providing commonly used dimensions, based on a width of 960 pixels. There are two variants: 12 and 16 columns, which can be used separately or in tandem.
