In the first detailed road map since the two companies struck an agreement Nov. 2, Microsoft said it will release a service pack for Microsoft Virtual Server 2005 in the second quarter that will let Novell's SUSE Linux Enterprise Server 10 run as a virtualized guest OS.

Work will also be done on the still-under-development, and still officially unnamed, "Longhorn" server -- the successor to Windows Server 2003 -- so that it can host SUSE Enterprise Server 10. In turn, SUSE's implementation of the open-source Xen virtualization technology will be able to host Longhorn. The former will require the new Windows Server virtualization, which Microsoft has promised to deliver within six months of the release of Longhorn server.

"Customers wanted ways for Linux and Windows to work together," said Bob Tenczar, Microsoft's director of product management for Windows Server. "And [server] consolidation was chief among them."

For its part, Microsoft is producing adapters to allow SUSE Linux Enterprise Server 10 to run on the Microsoft hypervisor, while Novell is prepping its Xen hypervisor for Longhorn. The two companies, which in November promised to set up an interoperability lab, have yet to detail the lab's location or staffing, but engineering teams from both companies have been collaborating on virtualizing each other's operating systems.

"The joint teams have really been working since Nov. 3," said Tenczar. "They spent the past 100 days deciding on what to deliver." Microsoft and Novell have been sharing code as they work on virtualizing Longhorn within SUSE's Xen and enabling Longhorn to host SUSE in a virtual machine, he said.