FireBug is a new tool for Firefox that aids with debugging Javascript, DHTML, and Ajax. It is like a combination of the Javascript Console, DOM Inspector, and a command line Javascript interpreter.
January 2006
FireBug – Debug AJAX, DHTML and JavaScript from within Firefox
Access Firefox settings via keywords
LifeHacker.com has published a neat tip to quickly access Firefox settings dialogs (e.g. Options, Extensions, Bookmarks, etc.) without using the mouse.
Optimised Firefox builds for the Mac community
Got a Mac? Want bleeding edge optimised versions of Firefox specifically for your G3/G4/G5 processor? Follow the link below.

Link : Firefox Mac Community Builds
10 Must Have Firefox Extensions
Rob Gonda has collated a fine list of developer oriented Firefox extensions.
FireFox Web Developer extension hits 1.0!
The honour of the first official FirefoxHint goes to Chris Pederick and his incredible Web Developer extension. This is indespensible for doing any web related work.
Link : chrispederick.com Blog – Web Developer 1.0 – December – 2005
A year in the making but well worth it. Congratulations – and thanks to Chris.