If we are developing websites and applications, we test them in different browsers, and on different platforms, right? So you might have a couple of machines in another room where you work, and you’ve agreed with your IT guys that you want to leave Internet Explorer 6 and Firefox 1.5 or 2 running on them, so that you can test your creations.
Just for example.
But then, someone helpful upgrades to the latest versions, and your ad hoc testing envrionment is no more. Yes, there are better ways to set things up – I could run Parallels on my Mac, install Windows, and then have whatever dodgy old web browsers I want on there. But for various reasons, I don’t.
Anyway, it came to pass that I wanted to run Firefox 2 and 3 simultaneously on my Mac. I was already running Firefox 3, and I knew that if I simply downloaded the installer for v.2, I would overwrite what is there already. Hmmm. So now what?
Answer 1: create a new Firefox profile, install both versions of Firefox, and use the command line (from Terminal [Mac] or Run… [Windows]) to control which version of Firefox you open
Answer 2: create a new Profile, and install the MultiFirefox app [Mac OS X only] to control it all.