Red Hat and others at the O'Reilly Open Source Convention gave Microsoft a hostile reception. Craig Mundie, senior vice president of advanced strategies at Microsoft, said in a speech at the convention in San Diego that his company is embracing several of the beneficial aspects of the open-source movement. But while stating that Microsoft didn't have anything against open source itself, he took issue with the General Public License that underlies much of the code-sharing movement. "Our concern about the GPL is strictly the fact that it creates its own closed community," Mundie said, referring to the licence's requirement that new software being added to a GPL-governed program must also be governed by the GPL. Earlier in the year, that feature led Microsoft chief executive Steve Ballmer to call open-source software a "cancer" and Windows leader Jim Allchin to call it "an intellectual-property destroyer." As an alternative, Microsoft in May came out with its own "shared source" plan, a collection of licences that makes it easier for business partners and curious people to see Microsoft's source code without requiring the company to relinquish control the way the GPL would. But Microsoft's foes were having none of it. "This shared-source thing has nothing to do with building community outside of Microsoft," Red Hat chief technology officer Michael Tiemann said in a speech immediately after Mundie's. "It is not so much a licence, I think, as it is a treaty crafted by executives trying to buy time while they quiet the internal rebellion that is Microsoft's own civil war." Rubbish, Mundie responded in a debate. "I can tell you quite specifically there's no civil war at the management level and no observable civil war among the rank and file," he said. The open-source movement is an offshoot of the free-software movement founded in 1984 by Richard Stallman, who set out to clone the Unix operating system under a project called GNU, or GNU's Not Unix. Free-software advocates emphasise that they use the term "free" to mean liberated from proprietary constraints, not zero-cost. Mundie said Microsoft favours a commercial software strategy that tries to emulate some of the favourable aspects of the open-source movement. Among those benefits: a common intellectual pursuit that takes place in a broader environment than just academia; the ability to share code with business partners and customers; and a stronger community of programmers. To offer evidence of the success of Microsoft's shared-source program, Mundie said 10,000 people have downloaded the source code to Windows CE in the first three days since Microsoft offered it for non-commercial use. Mundie's speech was part of a months-long campaign to cast doubt upon the legal underpinnings of the open-source movement. That movement has not only spurred successful projects such as the Linux operating system and the Apache Web server, which have won broad industry support, it has also triggered the formation of countless lively groups of collaborating programmers, who are often opposed to Microsoft. But Mundie on Thursday tried to back away from the harsher position Ballmer and Allchin have taken. "Let me be clear," he said. "Microsoft has no beef with open source. We think it's an integral part of an ecosystem that has fuelled such growth around the world in the software and information technology business." Mundie's criticism was more vague but further reaching. "The big concern Microsoft has is the long-term preservation of what we consider the software ecosystem," he said. During a debate and question-and-answer period after the keynote speeches, several open-source advocates and free-software fans took the opportunity to question Microsoft's motives. Brian Behlendorf, a co-founder of the Apache project and chief technology officer of group programming site CollabNet, said part of Apache's success was that companies that used the software gave their contributions back to the project. What's missing from Microsoft's shared-source program is this "bidirectional" exchange "that puts all participants at an equal level." Bradley Kuhn, vice president of the Free Software Foundation, said, "Microsoft has stated that the GNU GPL is an un-American cancer" and challenged Mundie to debate the issue at a coming Free Software meeting in October. Mundie declined to commit to the meeting. Others expressed worries about Microsoft's lobbying efforts. "I'm very concerned that an effort to characterise open source and free software as bad for public policy could be undertaken, and more concerned that it might succeed," said Mitchell Baker, author of the open-source license under which the Mozilla Web browser is released. "There's no attempt on our part to characterise open source as bad or bad from a policy point of view," Mundie responded, drawing boos from the audience. Tiemann was unconvinced by Microsoft's warmer stance. "It sounds to me like the logging companies who will be really nice guys as long as you let them cut down trees or the oil companies that will be nice to the environment as long as you let them drill oil," Tiemann said. "To build an architecture of trust, it is better to be open than to seem open, better to be trustworthy than to seem trustworthy." Find out how the open-source movement is revolutionising the high-tech world at ZDNet UK's Linux Lounge. Have your say instantly, and see what others have said. 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