Apple is notoriously protective of its operating system because, despite creating insanely good software, Apple is, primarily, a hardware company. Most of its operating profits come from selling computers and other devices that it designs and builds. Apple is afraid that through the magic of virtualization, it's only a short step from running multiple copies of OS X on a Mac to running OS X on a generic non-Apple PC -- and that is something that, at least at present, Apple has no interest in allowing.

Apple typically refuses to comment about unannounced products, and the company did not deviate from that policy when we contacted it for this story. But it would not be surprising to see Apple find a way to address this issue and allow virtual OS X instances -- if it could do so without opening the door to OS X on non-Apple hardware.

So for now, you can run Windows virtual machines on a Mac but not Mac virtual machines on a Mac -- and certainly not Mac virtual machines on a PC. Although Apple may claim bragging rights for building the most flexible, compatible computers on the planet, pressure will be building fast for virtualization solutions to support running multiple copies of OS X on Macs.

Richard Hoffman is a writer, systems architect and technology analyst who is proud to claim decades of pre-chic geekdom. He can be reached at rhedmail@mythosphere.com.