MacWorld has a list of top ten Firefox extensions for geeks:
Mozilla’s Firefox browser is a great tool for surfing the Net. And thanks to a growing number of free Firefox extensions, it’s an especially good tool for people who want every possible ounce of browser power—and who are willing to tinker with their Mac to get it. I’ve dug up 10 of the best extensions for Firefox (). Some of these are designed to make surfing easier or safer, while others are specifically geared toward Web developers. All are free, and you can easily configure or remove them in Firefox by going to Tools: Extensions.