The release of version 3 of Firefox was one of the most awaited moments in software and download history. However, as with any new piece of software, this iteration is bound to have bugs and issues that should be corrected in the future.
MultiFirefox is an ingenious little tool for Mac that will allow you to run up to five different versions of the browser alongside each other. It can be extremely useful if you're a developer and want to see how your website appears in the different versions of the version. MultiFirefox can also be used to go back into the history of the Mozilla browser and see how the different versions evolved over the years.
The application comes with a copy of Firefox 3, which you'll have to install if you haven't done so yet. Unfortunately, you'll still have to install all the other versions that you might want to test out. Switching between versions from MultiFirefox's interface is quick and easy however the program at times fails to indicate the number of each version.
Looking to test out your website in different versions of Firefox? MultiFirefox is what you're looking for.