When designing for the Web, one must be constantly mindful of the wide variety of Operating System/Browser combinations that are possible, and the varying results in rendering when it comes to these. If you’re a Mac user, you may find it difficult to debug your pages in Internet Explorer without having access to a Windows PC. Luckily, due to the recent move to Intel processors, Mac’s now have a whole bunch of different software solutions for Windows Virtualization, and recent improvements in this field offer even more seamless integration with OS X than ever before. One of the most popular applications for Windows Virtualization on the Mac is Crossover, which is based on WINE. While the premise of this app is great, it simply isn’t stable or reliable enough for repeated use.

VMware Fusion has my support as the best Virtualization solution. You choose to either boot up a fully-fledged Windows XP or Vista installation, or just open single applications from the OS. The Windows applications are “unified” with OS X, and are displayed as standard independent windows within the Mac OS. For example, I’ve added icons for Internet Explorer 6 and 7 (both Vista and XP versions) in my Dock, clicking these opens the apps in their own windows, seemingly absent from Windows XP/Vista.

Sure, it’s probably not worth throwing out your XP/Vista test box just yet, but if OS X is your only available system, then this certainly will allow for some comprehensive testing across multiple platforms.