Firebug exists and is great in some ways, but it is dog slow for complex apps. Chrome's dev tools blow it out of the water. The Firefox team has been doing an

Firebug exists and is great in some ways, but it is dog slow for complex apps. Chrome's dev tools blow it out of the water. The Firefox team has been doing an awesome job on the native dev tools lately, and they're fast. If you haven't tried them out recently, you should.