For those wondering how Microsoft partner Citrix's purchase of open-source vendor XenSource would affect Citrix's relationship with Microsoft, the September 11 announcement involving the two does little to answer that question.
At the VMWorld 2007 show, Microsoft and Citrix announced they have "strengthened their longtime (18-year!) integration alliance in the desktop application delivery market." The specifics (from Microsoft's press release):
Citrix and Microsoft both will be "standardizing on the Microsoft Virtual Hard Disk (VHD) format as a common runtime environment for both virtualized operating systems and applications. This collaboration will result in future versions of Citrix’s Desktop Server and virtual application solutions adopting the Microsoft VHD format. At the same time, Microsoft plans to adapt a future version of Microsoft SoftGrid Application Virtualization for both the desktop and Terminal Services to the VHD format. Microsoft and Citrix will also collaborate on emerging virtualization technologies and virtual infrastructure management tools to help ensure interoperability and simplified administration for end users."
Was there any doubt Microsoft would back its own VHD format? I wouldn't think so. And it sounds like Citrix and XenSource already support VHD, too. However, Citrix is planning to extend its support of VHD "to include operating system streaming to both servers and desktops," the release notes.
Microsoft also announced last week that the next version of its System Center Virtual Machine Manager (SCVMM) product will manage not just Microsoft's own software, but virtualization products from some of its competitors and partners, as well. Timed to roll out around the same time Microsoft delivers Viridian, a k a Windows Server Virtualization (which will be anywhere from the second to third quarter of 2008), the next version of SCVMM will manage virtual machines an dapps running within Viridian, Microsoft Virtual Server, VMWare and Xen.