I’ve had my web developer hat on a little too often of late and been suffering from one of the problems most developers loathe – testing how a site looks in earlier versions of Internet Explorer. (Yes, I know IE6 must die) but when a client’s IT department won’t let them upgrade because they have some proprietary system that only works in IE6, there’s not much I can do about it – they need to see what their site looks like on their own machines (and they’re not allowed to install any other browser so they can’t test that either).
I’m a Mac user too, so I use Parallels Desktop for Mac to run Windows 7, which is great for testing sites in Windows versions of Chrome and Firefox, as well as the version of IE that’s installed on the system (I just upgraded to IE9, it’s really much better than previous ones). The problem comes with testing in earlier versions – you can usually only have one version installed at a time.
For simple needs
If your needs are just seeing a screengrab of how a page renders, then you can use the NetRenderer web service to see how things look in IE all the way back to 5.5.
For total fidelity
You can download various versions of Windows designed for testing web app/web site compatibility with different versions of IE, from 6 to 9 from Microsoft in VHD (Virtual PC Hard Disk) format. Through the use of some command line jiggery pokery, and the Parallels Disk Tool, it’s possible to transform that into a bootable Parallels Disk Image. The downside to this process is that these disk images expire and you need to go through the process every few months.
A happy medium
The best solution I’ve found is IETester from DebugBar, makers of a code debugging solution for IE. It’s in alpha, but apart from the occasional quirk and crash (check their known problems list to see if there’s anything there that affects you), I’ve found it to be by far the best way to run side-by-side comparisons in multiple versions of Internet Explorer on my Mac, from IE 5.5 right through to IE 10 Preview. It’s free too – though you can make a donation for their efforts.