Martin Taylor, best known for his role in leading Microsoft's anti-Linux 'Get the Facts' campaign, has abruptly left the company - just as one of his chief foes began a joint effort with the company.

"We've made the difficult decision to part ways with Martin, but we don't comment on personal matters," Microsoft said through its public relations firm Waggener Edstrom. "We appreciate Martin's contributions at Microsoft over the past 13 years."

Taylor, who most recently was a corporate vice-president for Microsoft's Windows Live services, was quoted in a Microsoft press release announcing the introduction of Windows Live Messenger on Monday. Yesterday, published reports announced that he had left the company.

Prior to working in Windows Live services, Taylor spent several years as general manager of platform strategy, a job in which he was the spokesman for 'Get the Facts', Microsoft's anti-Linux initiative, criticising Linux' reliability (read our interview with him on the subject).

According to the company, Get the Facts was a campaign that educated users about the true cost of implementing Linux compared with Windows. However, many viewed it as a blatant attack on Linux at a time when the open-source OS was eating away at Windows Server's share of the Intel-based server market.

Taylor's brisk departure comes at the same time as the surprise announcement that Microsoft is working with a major critic from the open source field, Lawrence Lessig, to facilitate Creative Commons licences within Office documents. Stanford law professor Lessig, last year bitterly criticised Microsoft for tactics such as Get the Facts, accusing it of carrying on "all out war" with open source, and Linux in particular.

Since last year, Microsoft has been making overtures towards open source advocates, including Lessig and Michael Tiemann, president of the Open Source Initiative (OSI).

Before his anti-Linux role in Microsoft, Taylor worked closely with Microsoft CEO Steve Ballmer as a director of business strategy. He could not immediately be reached for comment.