The RoR plugin that would let you write your css files in ruby (erb, ie style.css.erb) which would compile to css. That way, you could write perfectly standard css code, and it would output several css files that are quirks compliant.You could make several stylesheets like layout.css.erb and tabs.css.erb and so on… and once you’ve out your app in production, it would flatten all of them into one file, and minify it.