Firebug extension
Saturday, August 4th, 2007Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.
Firebug features:
Just the way you like it
Firebug is always just a keystroke away, but it never gets in your way. You can open Firebug [...]