SEATTLE (AP) – Microsoft Corp. said Monday it will share technology with Linux distributor Xandros Inc., the latest in a string of deals meant to help the patent-protected Windows operating system work more smoothly with open-source programs.

Under the terms of the agreement, New York-based Xandros, which makes and distributes open-source desktop and server software, will license server code from Microsoft and develop software tools that work with Microsoft’s systems.

The companies also will work on technology to translate between two types of documents, Microsoft-developed OpenXML format and the Open Document Format. That could improve interoperability between Microsoft’s Office software and open-source rivals.

Microsoft also said in a statement it will endorse Xandros Server and Desktop programs as a preferred Linux distribution.

Key to the agreement is a clause that protects Xandros customers from running afoul of Microsoft’s legal machine for patent infringement. A growing number of companies and government agencies rely on elements of both Microsoft’s Windows and various versions of Linux to run their office networks, but fear being sued by the software maker, which claims open-source software infringes on hundreds of its patents.

Financial terms of the arrangement weren’t disclosed.

The Linux server software segment is dominated by Red Hat Inc. and Novell Inc.; Xandros’ share of that worldwide market is so small that research group IDC doesn’t track it. Xandros captured less than 1 percent of the desktop Linux operating system market in 2006, according to IDC, far behind big players like Red Flag Software Co., based in China, and Turbolinux Inc. in Japan.

The deal with Xandros is similar to one Microsoft struck with Novell last November. It sparked considerable outcry from some open-source programmers, who make all of their code – and any software that includes their code – available without charge to users and other developers.

Free software proponents argued that under the public license governing Novell’s code, Microsoft must give up patent claims on its software if it makes exceptions for some customers.

In a May filing with the Securities and Exchange Commission, Novell noted that Microsoft could conceivably back out of the deal to avoid extending its patent covenants to a broader range of recipients.