In a significant acknowledgement of the viability of Linux as a desktop OS, Microsoft Corp. today announced a deal with Novell Inc. to support Suse Linux on machines that run Windows.

Microsoft will offer sales support for Suse Linux and also co-develop technologies with Novell to make it easier for users to run both Suse Linux and Microsoft Windows on their computers.

As expected, Microsoft CEO Steve Ballmer announced the news in a San Francisco press conference. As part of the deal, Microsoft also will agree not to assert rights over patents to any software technology that might be incorporated into Suse Linux.

Microsoft has been relenting lately on its tight hold on patents through a program called its Open Specification Promise. Through the program, Microsoft has promised not to take any legal action against developers or companies that want to use specifications for a host of technologies for which it has patents.

The deal between Microsoft and Novell will certainly be a blow for Red Hat Inc., the second in as many weeks. Last week, Oracle Corp. said it would begin selling technical support for Red Hat Linux, a plan that both validates Red Hat Linux while undermining Red Hat's own support and maintenance business. Red Hat is the leading supplier of Linux and the biggest rival for Novell's Suse Linux distribution.

Novell built its business on the back of its NetWare network operating system, but the appearance of Windows NT on the scene as a viable alternative was a primary reason for NetWare's ultimate demise. In recent years, Novell has rebuilt itself into an open-source software company through purchases of companies such as SUSE Linux AG and Ximian.

The deal also will not only pit Microsoft and Novell against Oracle and Red Hat, but also IBM, which was an early supporter of Linux, particularly Red Hat's distribution.