mjasay writes "Microsoft is advertising for a new director of open source strategy, but this one has a specific purpose: fight the Linux desktop. 'The Windows Competitive Strategy team is looking for a strong team member to lead Microsoft's global desktop competitive strategy as it relates to open source competitors.' For a variety of reasons, this move is almost certainly targeted at Ubuntu Linux's desktop success. With the Mac, not Linux, apparently eating into Microsoft's Windows market share, what is it about desktop Linux, and specifically Ubuntu, that has Microsoft spooked?" Reader christian.einfeldt notes Microsoft's acknowledgment of the FOSS threat to their business model within SEC filings, and suggests that this job posting could instead be about maintaining Internet Explorer's market share lead against Firefox.