I’ve been saying for awhile now that Firefox is one of the better tools a tester can have in their toolbox when dealing with web applications largely due to LiveHTTPHeaders and Firebug. Looks like it is time to add another blade to the jackknife with the release of YSlow.

It looks like the rules that it is checking against form the basis of the new book High Performance Web Sites: Essential Knowledge for Front-End Engineers.

More information can be found on the O’Reilly Radar post that alerted me to it.