Though there are a couple minor bugs, it works fantastically for testing IE6, 7, and 8 without jumping through hoops.
Combine IETester with Safari for Windows, Firefox 3 (and 2), Opera, and perhaps Chrome and you've got a full suite of browsers to test with just on Windows. For the most part, that will give an accurate view of how it will look on Mac and Linux, but it doesn't hurt to have a VM of both a Linux distro and (cough) OS X available to test properly with.
Though there are a couple minor bugs, it works fantastically for testing IE6, 7, and 8 without jumping through hoops.
Combine IETester with Safari for Windows, Firefox 3 (and 2), Opera, and perhaps Chrome and you've got a full suite of browsers to test with just on Windows. For the most part, that will give an accurate view of how it will look on Mac and Linux, but it doesn't hurt to have a VM of both a Linux distro and (cough) OS X available to test properly with.