Microsoft has pegged Longhorn's release for the second half of 2007.

Betas of the Virtual Server 2005 R2 service pack and Longhorn will be available, but Microsoft wouldn't set dates for the release of those test versions. "We'll be demonstrating interoperability later this year at conferences" and the like, added Bill Hilf, general manager of Microsoft's platform strategy.

In a separate announcement, Novell said it would also roll out drivers later this year that would let Windows 2000 Server, Windows Server 2003 and Windows XP run as virtual machines in SUSE Linux Enterprise Server 10's Xen technology. "This is completely separate [from the Microsoft deal]," said Justin Steinman, Novell's director of product marketing for Linux and open source. "We've been doing this work with Intel since April 2006."

The Windows Server 2000/2003 and Windows XP virtualization within SUSE depends on Intel's homegrown virtualization built into some of its desktop and server processors, including the Xeon line.

Novell, said Steinman, added support for Windows Server 2003 when it made its pact with Microsoft in November. Because of the deal, support for virtualized Windows Server 2003 on SUSE will be available from both Microsoft and Novell. Support for Windows 2000 Server and Windows XP, however, will be handled by Novell alone.