VMware Challenges Microsoft Licensing

Alleging that Microsoft is “trying to restrict customers’ flexibility and freedom,” the company’s main competitor in virtualization technology has published its complaints in an open letter on the Internet.

VMware, which is estimated to have about 80% of the commercial market for virtualization, claims that Microsoft is using licensing restrictions to prevent customers from making effective use of technologies such as VMware’s Vmotion, which can migrate running virtual machines (VMs) among different physical servers (to balance server workloads, for example).

VMware’s Complaints

Among other concerns, VMware asserts the following:

• Microsoft requires a costly Premier Support agreement if customers want support for virtualized systems
• Microsoft’s preconfigured Virtual Hard Disks (VHDs), files that encapsulate VMs, are licensed to run only on Microsoft’s Virtual PC or Virtual Server products
• When run on VMware’s platform, VHD users sometimes get a product activation prompt, which