• Windows Server 2008 Enterprise without Hyper-V: $3,971 (with 25 CALs)

• Windows Server 2008 Datacenter without Hyper-V: $2,971 (per processor)

• Windows Server 2008 for Itanium-based Systems: $2,999 (per processor)

• Windows Web Server 2008: $469

When the versions incorporating its Hyper-V virtualization technology become available, they will be priced as follows:

• Windows Server 2008 Standard: $999 (with five Client Access Licenses (CALs)

• Windows Server 2008 Enterprise: $3,999 (with 25 CALs)

• Windows Server 2008 Datacenter: $2,999 (per processor)

Microsoft said on Monday it will also release a stand-alone hypervisor for running other operating systems, called Hyper-V Server, priced at US$28 regardless of the number of processors. "If you have a machine that doesn't have Windows at all, then you would buy that in order to run instances of say Linux or Sun," Lees said.

Microsoft is continuing its cooperation with XenSource, a virtualization vendor, which was acquired by Citrix last month. That project enables both Windows and Linux machines to perform well if hosted in a virtual environment on the other OS.

"We have very tight integration of running Linux on Windows," Lees said. "It [Linux] runs incredibly well."

Lees said if virtual Linux runs well on Windows, it will ultimately make more people choose Windows Server. On the application side, however, "people will choose to run Linux with their applications or not based on the merits of Linux versus Windows," Lees said.

In other announcements, Microsoft made available on Saturday its FastCGI extension for its Internet Information Services 6.0 Web server. The extension enables faster use of application frameworks built in scripting languages such as PHP.

Microsoft will also release another Community Technology Preview of SQL Server 2008 this month.