Adam DuVander from the 
WebMonkey website team 
has compiled a list of the 
top five add-ons for Firebug . Outside of the competition, 
YSlow turned out to be, but the remaining 4 are also very useful:
* 
Firecookie for easy cookies
* 
FirePHP for server debugging integration with Firebug interface
* 
Pixel Perfect for imposing a layout on the HTML template to control the compliance of the layout
* 
Rainbow for highlighting Javascript syntax
Use.