Microsoft has signed another Linux distributor to a patent-licensing and collaboration deal similar to the one it struck with Novell last year.

Xandros, which offers desktop and server versions of Linux, has agreed to license Microsoft intellectual property (IP), said Bob Muglia, senior vice president of the Server and Tools Business at Microsoft. He dropped the news in the middle of a keynote Monday at the company's TechEd 2007 conference in Orlando.

Muglia shed little light on specific details of the agreement, saying only that it follows the same model as the Linux and Windows interoperability and licensing deal Microsoft struck with Novell last year.

"Xandros has taken a license to our intellectual property," he said. "They've taken the position of helping customers to ensure that when they use open-source software, that the IP the industry has created is a part of that."

A news release the companies made available Monday had more details, confirming that the deal includes "covenants" to protect customers using Xandros software from any potential patent-infringement claims from Microsoft.

Microsoft said recently it would aggressively seek royalties for patents it says it holds in open-source technologies such as Linux. The company acknowledged that instead of going to court it would rather sign back-room patent and cross-licensing deals with open-source distributors.

Muglia acknowledged that in the past year Microsoft has stepped up efforts to ensure its products are interoperable with competitive offerings, and working with the open-source community has been a big part of that.

"Over the last year, you've seen Microsoft take a number of steps that ... demonstrate a change of approach for us," he said. "You've seen partnerships you might not have expected Microsoft to be a part of." Muglia mentioned partnerships with Xensource, Novell and JBoss as examples of the company's new attitude.

In addition to the licensing component, the five-year deal between Xandros and Microsoft also will include collaboration between the companies to make their Microsoft System Center and Xandros Systems Management products more interoperable. Xandros also will join the efforts to standardize and use Web Services (WS)-Management protocols, which Microsoft supports.

As part of the deal, Xandros will license Microsoft server communications protocols so Xandros Server will work better with Windows Server in IT systems. The company also will join the effort to build translators between rival document formats Open Document Format, an international standard favored by open-source companies, and Open XML, Microsoft's default format in Office 2007.

Finally, Microsoft will endorse Xandros desktop and server Linux OSes as the "preferred" distribution for its customers, and company engineers will be trained to support the software to help channel partners offer both Microsoft and Xandros software.