VMware has slammed Microsoft's virtualization licensing and distribution policies as restrictive and anti-competitive. In a multi-page white paper posted Monday on its Web site, the Palo Alto, Calif. leading virtualization software company came out swinging, alleging that Microsoft is "forcing" its virtualization APIs and formats on the industry and leveraging its leading server applications such as Exchange, SQL Server and Windows Server to force customers to use Microsoft's virtualization offerings.
Microsoft currently offers a standalone Virtual Server 2005 and Virtual Server 2005 R2 but is busy building its next generation virtualization hypervisor into its next major Windows server upgrade, code-named Longhorn. The hypervisor, code named Viridian, will ship as an add-on to the Longhorn Server but eventually will be integrated into the server operating system, Microsoft promises. That could stem the popularity of VMware's software layer, which resides between the bare metal server and applications, as a substitute for the operating system.