Quoting from the Microsoft official announcement:
Microsoft Corp. and Sun Microsystems Inc. today announced that Sun has signed on as a Windows Server OEM. Additionally, Sun and Microsoft will collaborate to further enable deployment of Windows Server on Sun x64 systems.
…
Sun and Microsoft will work together to ensure that Solaris runs well as a guest on Microsoft virtualization technologies and that Windows Server runs well as a guest in Sun’s virtualization technologies. Sun and Microsoft will work together on a support process for customers using the virtualization solutions. This joint commitment to customers ensures that Windows and Solaris will provide a solid virtualization experience….
The Sun virtualization technologies this press announcement is referring to is the upcoming implementation of Xen inside Solaris 10 called xVM.
Xen codebase contributors are already working to grant a smooth experience with Windows guest operating systems. This work will only get better considering that:
- XenSource has been acquired by Citrix, a long term Microsoft partner
- Microsoft has two critical deals in place with Novell and now with Sun, granting their Xen-based hypervisors interoperability with upcoming codename Viridian
- Virtual Iron, offering a Xen-based hypervisor as well, just entered the Microsoft Interop Alliance
It seems pretty evident Microsoft is influencing Xen development more than open source community itself.