Microsoft hypes its own hypervisor

Microsoft gave more details yesterday on its plans to launch Windows-based "hypervisor" software for running multiple operating systems.

Bob Muglia, senior vice president in the Windows Server Division, said at Microsoft's Tech Ed conference that the software will be "built directly in Windows and will allow companies to virtualise multiple operating systems".

Microsoft CEO Steve Ballmer first mentioned the hypervisor plans in April at the company's Management Summit conference. Such software allows multiple operating systems to run on the same computer, a feature that's useful for consolidating servers in order to save money, and for extracting as much work as possible from a single system.

Muglia said the hypervisor software will be delivered in 2007, following the debut of Longhorn Server. The new software will take advantage of virtualisation technology coming from chipmakers Advanced Micro Devices and Intel next year, Muglia said.

The software will differ from Microsoft's existing Virtual Server product, he added. That product runs on top of Windows and can run multiple Windows sessions. A recent update to Virtual Server allows companies to run Linux and other operating systems as well.

The new software will instead be built directly into Windows. "We will build a thin hypervisor that sits on top of the hardware and virtualises resources such as CPU and memory, so it has the ability to create OS sessions," Muglia said.

"One of those sessions will have the virtualisation stack built into it to do device assignment and start and stop virtual sessions," he said. "It will have a version of Windows but will typically be a stripped-down version. That will control the other sessions, which can be Windows, Linux and anything that runs on x86 hardware such as Solaris or Linux."

And what about the Mac OS, now that Apple has said it will begin using Intel chips? "It's impossible to say," Muglia said. Apple CEO "Steve Jobs does not intend to allow the Mac OS to run on non-Mac hardware, so I don't even know what that would mean at this point."

Microsoft hasn't decided how to package and sell the software. It could come in a service pack release after the debut of Longhorn Server, Muglia said.

Microsoft's rival in this area is an open source software package called Xen, which has rapidly gained the support of AMD, HP, IBM, Intel, Novell, Red Hat and Sun Microsystems. Those companies have offered Xen support in the form of endorsements, programming help and software contributions. Xen doesn't yet support Windows, however.

In addition, VMWare recently expanded the capabilities of its existing virtualisation software. And IBM in February released the source code for a project called Research Hypervisor, or rHype.

Muglia said virtualisation software is relatively new, so the competitive picture isn't yet complete. "It will grow in importance but we're in the early stages of use," he said.

Mike Ricciuti writes for CNET News.com