Microsoft has unveiled the future of software distribution with the introduction of a virtual product evaluation program that lets users easily test server applications within a virtualised environment.

The VHD Test Drive Program, named for Microsoft's Virtual Hard Disk (VHD) format, will provide users with free preconfigured .VHD files that can be dropped onto any virtual machine that supports the .VHD format such as Microsoft's Virtual Server 2005, which also is free.

Users won't need dedicated servers or to manually configuration the server software to get up and going, according to Microsoft officials. The company also is allowing ISVs to distribute their evaluation software in the same virtualised manner.

The .VHD files provide users with evaluation copies of server software running on Windows Server 2003 R2 Enterprise Edition. The first .VHD files, which are available now, provide evaluation copies of SQL Server 2005, Live Communications Server 2005, Internet Security and Acceleration Server 2006 and Exchange 2007 (the 32-bit test version).

Microsoft also will provide Vista evaluation within a virtual machine in the first quarter of 2007.

While the program is designed to provide convenience for corporate software evaluation, it also hints at future commercial software distribution methods as virtual machine technology becomes more pervasive in corporate networks.

"The vision and roadmap is to drive down the path of being able to provide software that can migrate from the evaluation environment into the production environment for use in a commercial sense," senior director of Microsoft's virtualisation strategy, Mike Neil, said. "So today we are announcing the first step in looking at this as the test drive and the mechanism to be able to deal with evaluation software."

The .VHD files from Microsoft will time out after 30 days for those who download the files from the Microsoft website.

Those with MSDN subscriptions can use the evaluation software indefinitely as long as their subscription is up to date. For TechNet subscribers, the .VHD files will be active for 500 days.

"Once you have these files copied into your virtual machine, instead of having to go and find hardware and install an OS and then install the product, you are up and running in a matter of minutes," analyst with independent research firm Directions on Microsoft, Peter Pawlak, said. "They are trying to get people to play with products and eliminate some of the logistical and costs problems that prevent them from doing that. But this also is the first step into a new way of delivering software."

The program also allows ISVs to develop their own .VHD files configured with their software and make those files available for evaluation.

Microsoft has signed up 20 of its 7000 ISVs to participate in the program including, Altiris, BEA, Check Point, Citrix, CommVault, Dell, FullArmor, HP, Network Appliance, PlateSpin, Portlock, Quest Software, SourceCode Technology Holdings, Symantec and UGS.

"Customers have been asking us to do a virtual machine version that would eliminate the deployment issues," project research manager for Quest Software, Dmitry Sotnikov, said. "Our software works with Active Directory and Exchange and [customers] don't want to evaluate it in production so they have to set up a test environment and that takes time."

Sotnikov said Quest was one of the partners driving the initiative, which required that Microsoft make changes to its licensing agreements. Since the virtual test environment amounts to a redistribution of Microsoft software, ISV's had been legally blocked from offering .VHD files without consent from Microsoft.

ISVs now can sign a license for the VHD Test Drive Program, which includes the requirement that the ISV's virtual image display an end-user license agreement from Microsoft that users must agree to before they can deploy the virtual image.

Microsoft's VHD format has been available as a royalty-free license since May 2005 and was recently made freely available under Microsoft's Open Specification Promise.

The company has been beefing up its virtualisation story as it competes with VMWare and others. Microsoft has added licensing flexibility to its Windows Server line to ease the deployment of virtualisation technology, and the company plans to expand on that with Longhorn Server and its 'hypervisor" virtualisation capabilities. Earlier this year, Microsoft and XenSource signed a collaboration agreement to provide interoperability between Xen-enabled Linux and the Windows hypervisor technology.

Last week, Microsoft partnered with Novell in a wide-ranging agreement that included collaboration on virtualization technology designed to make it easier for corporate users to run mixed Linux and Windows environments.

Microsoft also plans to release next year System Center Virtual Machine Manager for managing a virtualised data centre. And the company recently bought Softricity, whose SoftGrid product is used for application virtualisation and the support of on-demand delivery of software including patches and upgrades.