Parallels, a Virginia-based startup, has released the final version of its Mac virtualisation software, two months after it began testing.

Parallels released the beta version of Parallels Desktop for Mac in April, a day after Apple launched Boot Camp, which allows Intel-based Macs to boot either Windows or Mac OS X.

Boot Camp itself followed enthusiast-led efforts that had created a successful, if somewhat clunky, way of booting Windows on Intel Macs.

What distinguishes the Parallels system is its use of Intel's Virtualization Technology (VT), built into new Macs running the Intel Core Duo. VT allows software called a hypervisor to create multiple operating system instances that all have direct, simultaneous access to the hardware, theoretically allowing virtualised software to run at near-native speeds.

VT is included in all new Mac Mini, iMac, and MacBook Pro machines, Parallels said.

That's in contrast to previous systems, such as Virtual PC, which simulate hardware in software. This approach means, for instance, that Windows could run on the PowerPC platform, but delivers far slower performance.

"We’ve broken through the barrier that previously kept Mac and Windows from effectively working together side-by-side, simultaneously, on one computer," said Parallels chief executive Nick Dobrovolskiy, in a statement.

Parallels is offering the software for $49.99 for the next 30 days, after which the price will rise to $79.99. The company said 100,000 beta testers from 71 countries helped work the bugs out of the test system.

The software isn't limited to running Windows on Macs; it can run Linux or any other x86-based OS on a Mac.

It supports features such as cut and paste between operating system virtual machines. Virtual machines can either run within a window, or expand to full-screen size on either the primary or secondary display, Parallels said.

So far Parallels Workstation is the only near-complete product of its kind available. VMWare has said it is running its system on Mac OS X in the labs already, and Microsoft has said it plans at some point to port Virtual PC to Intel-based Macs, but neither company has given a release date. Other Mac virtualisation projects, such as Free Q and Darwine (which uses different principles), are in their early stages.

CodeWeavers has said it plans to offer a Mac OS X version of its CrossOver Office software, which allows the Windows version of Microsoft Office to run on other platforms. The product has been available on Linux for several years.

Other approaches using a hypervisor tied into Intel VT include the open source Xen project.

Industry observers have noted that dual-booting is still superior for high-performance tasks, such as gaming, since it provides direct access to hardware.

Apple has said it has no plans to offer Windows virtualisation for the Mac.

Parallels also makes virtualisation software for Windows and Linux machines, and is planning a server virtualisation product aimed at small and medium-sized businesses for the middle of this year.