REDbot: <>
Oh, this is very handy indeed: a quick lint tool for HTTP so you can see what kind of headers are being sent. There’s a bookmarklet in the footer too.
Tags: headers
Thirteen Simple Rules for Speeding Up Your Web Site
The justification behind YSlow. If you've heard Nate Koechley speak, some of this will be familiar to you. It's all solid advice as far as I can tell.