I really like seeing companies build out their own style guide libraries. It's such a huge win in terms of maintaining css and keeping it consistent across an entire site/platform. We went through this process at Trulia about a year ago, and the results had a huge impact[1]. Sadly we never released our style guide to the public, but we did open source the tool for building it: https://github.com/trulia/hologram It tr…
Thanks for sharing this! Nicole Sullivan's talk about her work with Trulia was a huge inspiration for Yelp's styleguide.
The performance improvements you reported are very impressive. Well done!