Many applications share the same type of OS image, and can also be more easily moved from the customer's data center to the Windows Azure cloud service. On large scales, Microsoft officials claimed the approach can reduce management needs from thousands of specialized operating system instances to just a few generic ones that can be replicated thousands of times. On Patch Tuesday, this technology will also let IT treat the operating system and application separately, making it easier to apply security updates, Microsoft said.
Microsoft's over-arching goal is to put more focus on the application, rather than the virtual machine, which Greschler calls the "tablecloth," while the applications are the meal on top of it. Server application virtualization can even technically be used on physical servers that don't have a hypervisor installed, but it isn't likely many customers would do so.
Greschler is the co-founder of Softricity, which was acquired by Microsoft in 2006. Softricity had a desktop application virtualization technology ready to go at the time of the merger, and was working on server-side app virtualization as a side project.
Microsoft's "top priority was to make sure that App-V for desktop came out," Greschler says. The server app tool "was just in the labs. It was just a thought, 'well it would be cool.'"
Now it's a reality, but in fact Microsoft isn't the first to get here. The vendor AppZero boasts of its own server-side application virtualizaiton technology, which can move apps across physical and virtual servers and across VMware, Xen and Hyper-V deployments.
But Microsoft is faster to market than its chief virtualization rival, VMware, which virtualizes servers and desktop apps but not server apps.
"VMware currently doesn't support server application virtualization," VMware confirmed.
With System Center 2012, Microsoft is expanding its ability to manage multiple hypervisors. System Center already supported Hyper-V and VMware, and the new version will, in addition, be able to manage Citrix's XenServer.
But the tech-agnosticism doesn't extend to the server application virtualization. So far, this just works with Windows Server, and not Linux.