There are some Firefox extensions that are more useful than others, and one of the featured extensions over at Learn Firefox yesterday was StatusbarEx. It is probably one of the more useful extensions that I have seen because it not only displays the memory usage for your entire computer, but also for Firefox.
Using this tool you are able to monitor both the memory usage of Firefox as well as the CPU usage. That way you’ll be able to keep tabs (no pun intended) on possible memory leaks so that you can restart Firefox before it gets too slow.
The only thing that I couldn’t get to work was the network usage. It is supposed to show how much data has been transferred, but it always remained at 0K for me no matter which adapter I used. Oh well, being able to monitor the Firefox memory and CPU usage is worth enough in itself for me to keep this extension installed.
For more extensions head on over to Learn Firefox. Almost 50 Firefox extensions have been reviewed at this point, and there are dozens of other guides available on using and tweaking Firefox.