Parallels Desktop allows your Mac to run Windows XP (and other operating systems) alongside OS X on your Mac. I'm not going to do an in depth review. I will simply say that it works and it works well. The only software I have found that is not yet supported are programs using high-speed 3D graphics. Parallels' latest release features Coherence mode. That allows you to run Windows programs alongside OS X programs without having to switch into the Windows environment. Parallels' speed is quite good. It seems to run software nearly as quickly as it would run on a dedicated PC. Parallels supports other operating systems, like Linux variants, as well as Windows. It installs easily, the documentation is very good and the performance is excellent. Parallels is highly recommended.