"Microsoft is trying to restrict customers' flexibility and freedom to choose virtualization software by limiting who can run their software and how they can run it," states a white paper posted on the VMware site Friday. "Microsoft is leveraging its ownership of the market leading operating system and numerous applications that are market leaders in their respective categories... to drive customers to use Microsoft virtualization products."
The paper accuses Microsoft of closing the door on customer freedom of choice in a number of ways, including:
- Limiting support of any virtualized Microsoft product to customers at the "premier" level of support.
- Prohibiting the running of Microsoft virtual machines on third-party virtualization packages (like VMware's).
- Automatic deactivation by some Microsoft apps if Microsoft virtual machines are used with third-party virtualization products.
- A "VHD only" policy that means Microsoft virtual machines can't be translated into other formats.
- Limitations on how many hardware platforms a virtual machine can support.
- Prohibitions on virtualization of desktop OSes like Vista.
- Closed Windows virtualization APIs.
"Customers require freedom of choice to implement both Microsoft and non-Microsoft applications running on Windows with any chosen system virtualization layer," the document states. "Customers do not benefit from being forced into a homogenous virtualization/OS/application stack."
Microsoft, contacted by Byte and Switch, had the following statement from Mike Neil, general manager of Microsoft's virtualization strategy:
- "Virtualization has long been a core part of server operating systems and this dynamic market is enjoying a fresh round of innovation. These new technologies will help customers reduce costs, make IT more flexible, and enable vendors to offer more services. Microsoft believes the best approach for customers lies in establishing a foundation of cooperation between vendors, which is why we strive to regard virtual machines and virtualization technology the same way. Windows server licensing offers a level playing field to all.