Microsoft has hired a leading Linux engineering manager out of the den of one of its fiercest opponents, the San Francisco-based Linux Foundation.

Development veteran Tom Hanrahan, former director of engineering for the Open Source Development Labs and current director of engineering for the Linux Foundation, will be the new head of Microsoft's interoperability lab, one of the offspring of its deal with Novell last November.

The Linux Foundation is the group that was formed from the merger of the Open Source Development Labs and the Free Standards Group. The Linux Foundation has warned Microsoft publicly against attempting to enforce its patents against Linux users, a response to Microsoft's warnings on the heels of its Novell deal that it believes Linux violates some of its patents.

Hanrahan was previously senior program manager of IBM's Linux Technology Center in Beaverton, Ore., then joined the Open Source Development Labs in Beaverton at the end of September 2004.

Hanrahan will report to Sam Ramji, head of Platform Technology Strategy and Microsoft's Open Source Software Lab in Redmond. The lab has overall responsibility for interoperability between Windows environments and customer's open source code. It certified the operation of the JBoss Application Server and other middleware under Windows before JBoss' acquisition by Red Hat. Hanrahan will head the Linux interoperability efforts.

Hanrahan has 30 years of experience in engineering management and open source community development. He spent 11 years at Sequent Computer Systems, where he worked in software engineering. He also has worked for Intel, where he lead a team of technical writers focused on encouraging the use of software development tools and programming languages with the Intel chip set.

IBM acquired Beaverton-based Sequent as a wholly owned subsidiary in 1999. It is a firm that specializes in non-uniform memory access hardware -- large servers using up to 64 Intel processors for throughput but still able to cope with software aimed at a single-server. Sequent designs sought to avoid the demands of parallel programming required of large machines, such as NCR Corp.'s Teradata.

Hanrahan and Ramji report to Bill Hilf, general manager of Microsoft's Platform Strategy Group.