You can refer to the press release and the Q&A with Brent Callinicos, Microsoft’s corporate vice president for Worldwide Licensing and Pricing, but Ward Ralston has a nutshell summary at the Windows Server Division Weblog of the licensing changes coming December 1:
(1) Starting with Windows Server 2003 R2 Enterprise Edition – customers can run up to 4 virtual instances of Windows Server 2003 (any edition) with no additional licensing costs. Zero, nil. Additionally, Starting with Longhorn, If you purchase Datacenter Edition of Windows Server, you can have unlimited virtual machines – still at no additional cost. Pretty cool, huh?
And a nice incentive to get Datacenter.
(2) Some of our Windows Server System products are licensed by the processor. (BizTalk, SQL, Etc) When these technologies are run in a virtual machine, you only need to license for the virtual processors being used rather than for the physical processors in the host computer.
For Microsoft Virtual Server which only supports virtual uniprocessors this seems straightforward. However, the new licensing applies to any virtualization product including VMWare which does support virtual multiprocessors, so depending on what the VM’s are being used for, a little planning for optimal license usage might be required.
Finally, only the active instances (and not dormant copies) of virtual machines will require licenses and the licensing of active instances is portable among physical Windows Server machines. These are forward looking provisions for leading edge users of virtualization for dynamic workload accomodation.
Also in the press release: a list of companies was announced that are working with Microsoft on virtualization solutions and standards; there is an announcement that Microsoft will increase investment in management software for virtual machine environments; and
As part of its continued commitment to virtualization solutions, Microsoft will build virtualization capabilities into the Windows platform based on Windows hypervisor technology, planned for availability in the Windows Server “Longhorn” product wave.
That confirms the buzz that the equivalent of Virtual Server will become part of the Longhorn Server OS.