Windows-on-Mac software specialist Parallels has updated its Parallels Desktop virtual machine software, offering the new version in a pre-release test-only form. The upgrade packs in more than a dozen new features and fixes, the company said.

Those features most likely to appeal to Mac users keen to run Windows XP, include accelerated video performance, support for a wider range of USB devices - including Windows Mobile 5.0 smart phones and PDAs - full-screen operation fixes, and the ability to turn off the hard disk data cache Mac OS X maintains for virtual machines running within Parallels Desktop. That alone, the company said, can yield better Mac OS X performance. Or you can re-enable it for better virtual machine speed.

Separately, in an interview with Macworld US, Parallels said it is working on Windows Vista support, DVD burning, and adding "fast" 3D graphics support to the virtual machines its software enables.

Parallels' update is available here along with a list of tweaks.

The release of the update follows virtualisation veteran VMware's formal entry into the Mac OS X market and news from Microsoft that it will develop no further releases of Virtual PC. ®

Read Reg Hardware's in-depth report on running Windows on an Intel Mac here