SWsoft, a company that lets a Linux server be subdivided into independent partitions, is ready to begin testing a Windows version of its product

The software, called Virtuozzo, subdivides a single copy of an operating system so it looks like several. The software chiefly has appealed to companies that host low-traffic Web sites. Virtuozzo gives those companies a way to share servers but also offer customers some advantages of independent machines. To date, SWsoft has sold Virtuozzo only for Linux servers. A Windows version is currently in private beta testing, with broader testing scheduled to begin Nov. 22, and general availability scheduled for January, the company said. That's substantially later than the company projected. Two years ago, it said the Windows product would ship in the first half of 2003. The delay was required to bring the product to the same level of maturity and stability as the Linux product, the company said. Virtuozzo's approach, using a single operating system that looks to be several, is similar to N1 Grid Containers in Sun Microsystems' forthcoming Solaris 10. But Virtuozzo today competes more with EMC's VMware and Microsoft's Virtual Server 2005. One financial advantage of the SWsoft approach is that fewer operating system licensees need to be purchased. Hatsize, which offers infrastructure for online classes, is one company testing the Windows version. In addition, Virtuozzo has passed a certification test, ServerProven, for IBM's Intel-based xSeries servers. Australian hosting company WebCentral offers Virtuozzo as an option on xSeries servers, SWsoft said.