Macs that run Windows via virtualization are here to stay.

Boot Camp runs Windows operating systems (XP and Vista) and Windows-based applications, and it runs them fast and well and with excellent compatibility. In fact, early tests of Macs running Windows showed that Macs ran Windows apps faster than did many comparable Windows-only PCs. That's a huge change from the old emulation days.

But the one big flaw of Boot Camp is that you either run Mac OS, or you run Windows, but not both at the same time. If you need to switch from one to the other, it requires a complete reboot. That's fine if, as Apple intended, you have only one or two critical but infrequently used Windows programs, or if you want to spice up your Mac experience with a couple of Windows-only twitch games in your off hours.

But if you need to mix Mac and Windows programs on a more regular basis, all that booting and rebooting -- and the closing all of your open apps in between -- gets to be a real chore.

"True" virtualization comes to the Mac