Computerworld

Microsoft strikes back at VMware's attack

Microsoft releases another statement responding to VMware's attack on Microsoft's virtualization strategies

Microsoft Tuesday released yet another statement responding to an attack from VMware that criticized the software giant for licensing and technological restraints imposed within its virtualization technology.

The statement was a revision of a declaration made Monday that did not mention VMware by name. Tuesday's second version, however, took VMware to task for statements VMware published in a whitepaper on its Web site.

The feud was ignited by an article on VMware in the Feb. 24 issue of the New York Times in which the company claims Microsoft had recently introduced new restrictions on how its software runs inside virtual machines and changes to how a customer pays for the software.

Critics say the controversy could be the start of an industry battle, perhaps similar to the historic Microsoft/Netscape feud, as the virtualization market is poised to explode.

In Tuesday's response to the VMware attack, Microsoft sent a statement to media outlets from Mike Neil, general manager of virtualization strategy, saying: "Microsoft believes the claims made in VMware's whitepaper contain several inaccuracies and misunderstandings of our current license and use policies, our support policy and our commitment to technology collaboration."

Earlier this year, Microsoft restated its policy that only Vista Business, Enterprise and Ultimate versions could be used in a virtualized environment. Neil defended that decision in a posting on his blog Feb. 25, saying that virtualization was new for consumers and not yet mature enough from a security perspective for broad adoption. He did say, however, that Vista Enterprise lets users have four instances of Windows installed in VMs.

In the Tuesday statement, Neil went on to say: "We believe that we are being progressive and fair with our existing licensing and use policies and creating a level playing field for partners and customers."

Neil said Microsoft was committed to "high-quality" tech support and working toward interoperable virtualization technology.

He then turned the tables on VMware, saying "we believe it's better to resolve VMware's claims between our two companies so that we can better serve customers and the industry. EMC is a long-time partner of Microsoft. We've extended this courtesy to VMware due to our mutual customers and partnership with EMC. We are committed to continuing to collaborate with VMware as we have been doing on regular basis. Consistent with this, Microsoft believes that we will be able to accommodate a mutually agreeable solution between our two companies and clear up any existing misunderstanding with regard to the points raised in the whitepaper."

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In the whitepaper, VMWare lists a number of objections it has with the way Microsoft is approaching the virtualization market and what it is doing with licensing restrictions and other virtualization capabilities on the current Windows platform and upcoming improvement in Longhorn Server, including high-performance virtual machine technology called hypervisor.

In the summary of its whitepaper, VMware states: "Microsoft needs to fundamentally accommodate market choice and interoperability. Customers require freedom of choice to implement both Microsoft and non-Microsoft applications running on Windows with any chosen system virtualization layer. Customers do not benefit from being forced into a homogenous virtualization/OS/application stack."

VMWare said Microsoft needs to address those customers requirements and "needs to follow business practices, licensing and technology disclosure policies that result in the ability of Windows-based applications and OS's to be created, licensed, supported and distributed equivalently on Microsoft or non-Microsoft system virtualization stacks."

The company concludes that Microsoft is denying customer's choice by limiting who can run the company's software and how they can run it. Some of VMware's specific gripes include:

-- Microsoft has developed proprietary APIs (including but not limited to what Microsoft calls "Enlightenments") for Longhorn that manage communication between Windows and Microsoft's hypervisor.

-- Microsoft's Virtual Hard Drive (VHD) End User License Agreements forbid the conversion of the Microsoft VMs into any virtual machine format other than the VHD format.

-- Some Microsoft VHDs are now configured to de-activate themselves if they are run on any virtualization product besides Microsoft Virtual PC or Virtual Server.

-- Microsoft has posted language that restricts use of their VHD-formatted VMs ("VHDs") to MS Virtual Server and/or Virtual PC only.

-- Microsoft is restricting support to its Premier-level support customers.