In development for more than a year, Parallels Server for Mac will let users of Apple's Xserve and Mac Pro hardware to create virtual machines of Mac OS X 10.5 Leopard Server, in conjunction with Windows and Linux virtual machines (VM).

The software, which costs $999 per server and allows for an unlimited number of CPU cores (maintenance is extra), could encourage businesses seeking the efficiency and reliability provided by virtualization to take a second look at previously overlooked Mac servers.

Last November, Apple relaxed its server licensing rules so that its Mac OS X Server 10.5 Leopard operating system could run in a VM, provided that each VM is matched with a discrete license and the server hardware it runs on is made by Apple.

VMware said last week that Mac OS X server virtualization will be available in the next beta release of its Mac virtualization software, VMware Fusion 2.0.

Apple still forbids desktop and laptop versions of Mac OS X to be virtualized or run on non-Apple hardware.

However, Intel Mac users can run Windows VMs on top of Mac OS X using other software from Parallels (formerly known as SWsoft), VMware or Apple.

Parallels' Mac client virtualization software, called Parallels Desktop for the Mac, has the early lead over VMware Fusion, due to strong reviews and its faster time to market.

© 2007 Computerworld Inc.