Until now, Mac users who needed to run some Windows applications had to do so in emulation mode using tools such as Microsoft Corp.'s Virtual PC, which exacts a serious performance toll. But Apple's Boot Camp software, which was released for public beta testing with little fanfare, enables Windows XP to run on the new Macs just as it does on desktop and laptop PCs.

Boot Camp creates a hard-drive partition for Windows XP and lets users choose between it and Apple's Mac OS X operating system each time they start their computers. The dual-booting capability "definitely makes the Mac more attractive," said Micah Lamb, a microcomputer support specialist in the IT services department at Baylor University in Waco, Texas.

Lamb said via e-mail that Baylor often has end users who prefer Apple's hardware to PCs but need Windows in order to run applications central to their jobs. Boot Camp will let them have it both ways, he noted.

In addition, the new software essentially makes the Mac two computers in one, Lamb said. "You can buy a traditional Wintel box and run Windows only, or you can buy a new Mactel box and run both Windows and Mac OS X."

John Halamka, CIO at Harvard Medical School and CareGroup Healthcare System in Boston, said the school has about 4,000 Macs and a roughly equal number of Windows-based machines.