Microsoft said on Thursday that it has begun public trials of virtualization software that will compete with programs from VMware, saying the tests were starting ahead of schedule.

Microsoft's trial software, known as Hyper-V, is expected to come out in the first quarter of 2008. Microsoft's customers and partners today can download Windows Server 2008 RC1 Enterprise with the beta version of Hyper-V to evaluate the new technology. The beta is available for download at http://www.microsoft.com/ws08eval. Currently, the beta for Windows Server 2008 with Hyper-V is available for the x64 Enterprise Edition in English.

Trial version release comes on the heels of Oracle's unexpected entry into the market for virtualization software last month. Microsoft claims that Hyper-V is three times as efficient as VMware's product. Oracle has made a similar claim. On the other hand, VMware claims that Microsoft's new software does not provide the stability or advanced management functions that his company's product does.

A server using VMware software can simultaneously run five to 10 or more operating systems. Each of these systems becomes a virtual machine working as an independent server.

Microsoft plans to incorporate virtualization software in the first major upgrade to its business operating system for server computers, Windows Server 2008, to be released next year.