US software company Parallels has posted a pre-release version of its upcoming virtualisation tool for Intel-based Macs. Coming in response to the release of Apple's Windows XP-oriented Boot Camp utility, the Parallel product eliminates the need to choose which operating system the users at start-up. Instead, users can flip between operating systems at will.

Parallels also said the software doesn't limit users to Windows XP as an alternative to Mac OS X - they can opt to run "any version of Windows (3.1, 3.11, 95, 98, Me, 2000, NT, XP, 2003), any Linux distribution, FreeBSD, Solaris, OS/2, eComStation or MS-DOS".

Parallels' code, called Parallels Workstation, is available here, though the site appears to be experiencing heavy traffic.

It has been claimed by some observers that the Parallel application taps into Intel's Virtualisation Technology (VT), though at this stage that remains unconfirmed. Intel internal documentation seen by Reg Hardware earlier this year suggests that current Core Duo processors may not have VT enabled - the feature will not appear for certain until the chip giant ships its upcoming core update, which paves the way for the VT-supporting Core Duo T2700.

When we first reported on the possibility that current Core Duos do not have VT enabled, Intel officials were unable to categorically confirm that that was not the case. Other sources have claimed the chips do indeed offer VT - at least, when interrogated by software they list it as a supported feature, though this may simply be a case of applications assuming too much from the CPU ID.

Not that this matters to Parallels - without VT, it's software just has to do the heavy lifting itself, as virtualisation apps like VMWare previously had to. Once the code detects a VT-enabled processor, it can leverage the on-chip functionality and operate more efficiently. Certainly when VT is present, Parallels Workstation uses it "fully", Parallels said.

Parallels announced the Mac OS X version of Parallels Workstation 2.1 last week with a view to shipping the product this summer. ®