I love Firefox. It's a great browser, and my favorite part of Firefox is the extensions which you can add into to expand the browser's functionality.

Things such as ColorPicker, MeasureIt and Nuke Anything Enhanced I have long had on my browser. Lately, I've been playing around with GreaseMonkey. But I routinely look through the extensions to see if something new has been released that I would like to use or that would be helpful for me as a web developer. The last time I checked, I only found GreaseMonkey and Lori (a life-of-request information status bar extension). Tonight though, I had a bit of extra time and found myself three great new extensions.

• JSView. This extension allows you to view linked in files (such as style sheets and external JavaScript files). Quite often when I am viewing source, these files are what I'm hunting down to look at, so I think this is a great little tool for my toolbox.
• Header Spy. I'm not 100% certain on how useful this thing will be. But it's going to show me my HTTP headers on my status bar. It should be fun, at least for a bit.
• OperaView. I've long had IEView in my extensions list, as I find it useful to not have to launch the full browser, especially when I'm at home with only one monitor to look at. So when I found this one, I just had to add it into my little stash of things.

And of course, since I now also run GreaseMonkey, I also have to search for useful GreaseMonkey scripts.

Such as this one, which ensures that all URLs displayed in the browser are clickable links. I don't know how many times I've come across some blob of text, usually on some social or Web 2.0 website where it's a non-clickable URL. Unfortunately, the usefulness of GreaseMonkey scripts are not always 100% apparent.