Web security firm Netcraft says Microsoft.com has been switched to the former Longhorn, still in beta.

Microsoft recently switched its main Web site, www.microsoft.com, to Windows Server 2008, which is currently in beta 3 and publicly available for early adopters, a Web security firm said Wednesday.

Microsoft is running Server 2008, formerly Longhorn, and Internet Information Server 7.0, which already has been released, Netcraft said. IIS 7.0, however, is not expected to get much general use until the release of the latest Windows server, since IIS only runs on Server 2008 or Windows Vista. Windows Server 2008 is set for release this year.

Netcraft estimates that 2,600 Web sites are running the upcoming version of Windows server, with the majority separate from Microsoft. Developers and hosting companies are taking advantage of Windows Server 2008 availability through Microsoft's Go Live license, which allows beta software to be used for testing or a live environment without cost.

Once the final version of the software is released, it could take a long time for large numbers of sites to move over to the latest version, Netcraft said. The installed base of Windows Server 2003 took several years to overtake Windows 2000, and there are still about 5 million sites running on Windows 2000 today.

Besides the full-sized version of Windows Server 2008, Microsoft is planning a couple of down-market releases. Centro is the mid-market product, and Cougar is aimed at small businesses. Both are scheduled to ship in 2008.

Among the most highly anticipated features of Server 2008 is the Windows PowerShell, a command line shell with more than 130 management tools and an integrated scripting language. In addition, IIS 7.0 will be the built-in Web server, providing numerous online publishing technologies.