Currently an also-ran in a sector dominated by VMware and other open source vendors, Microsoft is striving to attract developers to its side by opening up its Virtual Hard Disk (VHD) Image Format specification.
The VHD image format gives server administrators a snapshot of what systems and applications are running on a given server.
Virtualization technology allows companies to run several applications on the same server, essentially fooling each application into thinking it has the server to itself.
The technology helps reduce investment in hardware and lowers power consumption considerably, because fewer servers need to be supported for the same number of applications.
In what can only be seen as a symbolic olive branch to the developer community, the company picked the Interoperability Summit in Brussels today to announce that it is opening its source code for this solution.
Last month, Microsoft announced that it was making its Web services specifications available for developers to use freely under an open source license it has dubbed the Open Specification Promise (OSP).
Bob Muglia, senior vice president of the Servers and Tools business at Microsoft, said this will help vendors develop products that connect diverse systems.
"By having the VHD specification available under the OSP, the technology is viable for any development or business model," Muglia said in a statement. "We continue to increase our commitment to interoperability in our products."
According to Charles King, principal analyst with Pund-IT Research, Microsoft is using VHD as a kind of loss leader in the hopes of developing long-lasting ties to the open source developer community.
"The company is laying the groundwork for future engagements with software developers, tools developers and other services developers for years and years to come," he told internetnews.com.
King also noted that its OSP commitment signals how seriously Microsoft is taking the virtualization and Web services markets.
"By the open specification promise they made last month, what they're saying is that these are technologies they see as game-breakers and that they plan to be there working as a partner with folks that are going to be engaged in these areas," he said.
The VHD specification also gives Microsoft an entry into a new market.
According to Gartner analyst John Enck, there are very few products on the market that allow server administrators to interact with the virtual images.
Currently, patches and other modifications to virtual servers cannot be performed while the system is at rest, which is a considerable limitation.
Microsoft wants to stimulate the development of a Microsoft-friendly ecosystem of tools and utilities allowing administrators to modify those virtual images.
"This is largely untapped territory," Enck told internetnews.com. "Microsoft wants to control the next layer of products as a way of counteracting the VMware engine."
But Microsoft is having to both play catch-up and bide its time.
John Abbott, who follows the virtualization market for the 451 Group, said that VMware currently has 90 percent of the server virtualization market.
Meanwhile, Microsoft doesn't plan to roll out its version of a hypervisor until 2008, he said.
It's current virtualization technology is based on assets acquired from Connectix in 2003.
In the meantime, therefore, it is moving aggressively by relaxing its licensing restrictions.
"It's a good move and a necessary move on Microsoft's part," he told