Today we're pretty well versed with how JavaScript works. We know that script elements block rendering (well, actually blocks the parsing, which thus delays the rendering), and we know why8. Sure, so we put the script elements at the end of the document. But did you know that link elements block too? * document.write can affect [...]

Firebug has a great built in JavaScript performance profiling tool, but it's not supported in IE and sadly that's what the bulk of Internet users browse with. In particular, IE profiling is something of a dark art. There's not a lot of resource available to profile that I could find that was particularly [...]