Microsoft\u00a0on Wednesday released a private beta of its upcoming Virtual Server 2004 and said the finished product would ship by the middle of the year.Virtual Server is a server-based application that allows multiple operating systems to run on the same processor at the same time. Supported operating systems include Windows Server 2003, Windows 2000 Server, Windows NT, Linux, Unix, and OS\/2. The Virtual Server application itself runs only on Windows Server 2003.The virtualization technology is being targeted at corporations looking to support legacy line-of-business applications running on older operating systems, most notably applications running on Windows NT that users want to keep on the operating system or eventually migrate. Support for NT expires at the end of this year.Those users could continue to run the application on NT, which would be hosted on the Virtual Server running on Windows 2003. The Windows Server 2003 operating system will be supported until 2008.\u00a0\u201cProducts like Exchange and Web servers have their own migration tools, but for line-of-business applications some additional work is needed,\u201d says Eric Berg, group product manager for Windows Server at Microsoft. The idea is that Virtual Server will help support those applications until that work can be done.Berg says the technology also could be used in a number of other cases.In the short term, Microsoft hopes the virtualization technology also will support consolidation of servers used to develop and test software.\u201cOne scenario is that companies could move development servers into a centralized server farm,\u201d says Berg. \u201cThey also could use the Virtual Server to get more developers per server.\u201dMicrosoft also will use Virtual Server as part of its emerging management platform called the Dynamic Systems Initiative (DSI). The Virtual Server will be married with Microsoft\u2019s Automated Deployment Services, an imaging tool, allowing users to provision virtual servers on a single box.Virtual Server 2004 competes with similar virtualization technology from VMWare and others.In the long term, Berg said the technology also is being looked at within the DSI model as a way to create a virtual platform in corporate data centers. \u201cYou could use it in production environments as a way to bring up server capacity when it is needed.\u201dHe said the technology also could be used in disaster recovery situations and to create a simulation environment for distributed applications such as those built with Web services.Microsoft acquired the Virtual Server technology from Connectix Corporation, which it bought in February 2003. Shortly after the acquisition, Microsoft released an alpha version of the Virtual Server as part of a customer preview program that drew 15,000 users. Those users along with 30 other companies are being supplied with the latest beta software.Pricing for Virtual Server 2004 has not been set.