RECESS : Developed at Twitter to support our internal styleguide, RECESS is a simple, attractive code quality tool for CSS built on top of LESS.
Incorporate it...
Foundation : An easy to use, powerful, and flexible framework for building prototypes and production code on any kind of device.
SpritePad : With SpritePad you can create your CSS sprites within seconds. Simply drag & drop your images and have them immediately available as one PNG sprite + ...
Reset CSS : The goal of a reset stylesheet is to reduce browser inconsistencies in things like default line heights, margins and font sizes of headings, and so on...
Sizzy : A tool for developing responsive websites crazy-fast.
Open sourced : https://github.com/kitze/sizzy