Yahoo Developer Network has been going great guns giving us YUI and what not. Now they have unveiled a new tool for measuring and fixing your site’s performance called Yslow.

Yslow measures your webpage on the 13 rules for speeding your site and returns you a report card of how your webpage performs against those rules as well as the list of offending parameters of your page.

it helps that it is a firebug extension which makes it a lot simpler in viewing the performance report and fixing the site based on the report. What also helps is the neat UI.

You can read more about web performance on the Yahoo Developer Network’s Performance team page