Nicole Sullivan covers some of Antti Koivisto’s work on making CSS selectors faster in WebKit. Clever stuff, which Nicole helps make understandable for all of us. Mostly stuff that helps the browser “rule out” selectors more quickly. I hope other browsers can take the ideas and use them where they can and continue their own innovations. Selector performance is already something that we pretty much don’t need to worry about it, I’d love it if we never had to think about it again.