Spectre.css : Spectre.css is a lightweight, responsive and modern CSS framework for faster and extensible development.
lightweight and clean starting point for your...
UnCSS : UnCSS is a tool that removes unused CSS from your stylesheets. It works across multiple files and supports Javascript-injected CSS.
Diagnostic.css : Diagnostic.css is a stylesheet which allows the user to test for common errors in a page's markup.
Also : https://github.com/karlgroves/diagnostic.css
