If the shinyness and world-record-breaking hype of Firefox 3 had you upgrading last week, you will have noticed a few things.

One: FF3 is pretty bad ass.

Two: Some of your plug-ins are not going to work in FF3, especially if you use some obscure ones. And then there is the old web development mantra of “But does it work in <insert browser name + version here> ?”

MultiFirefox attempts to make the whole process easier, by managing multiple profiles easily and making switching between them simple.

MultiFirefox is only available for Mac at the moment and is on Donationware, but it looks like it could be very helpful to the web development crowd