Contrary to popular myth, Microsoft doesn't hate everything about open source. While Microsoft officials publicly vacillate between declaring Linux either the most hyped operating system or the biggest threat to Windows, in reality, the company has learned some powerful lessons from its open source competitors. In fact, during the past six months, Microsoft has made available to "hundreds" of its larger customers copies of its Windows source code, said Doug Miller, group product manager with Microsoft's Windows .Net server marketing group. "Our goal is to make this [source code] available to many hundreds of customers," Miller said, during an interview at the LinuxWorld Conference and Expo trade show in New York this week. Source code is the set of underlying programming instructions that comprise an operating system. In general, open source refers to software such as the Linux operating system that is allows programs to be modified by users. By contrast, Microsoft has retained tight control over the Windows source, which company executives have called Microsoft's "crown jewels". Microsoft has licensed elements of the Windows source code to less than 100 software and hardware developers working closely with Microsoft on evolving the operating system, according to estimates by sources close to Microsoft. The company also has licensed the Windows source to universities and government bodies under restrictive terms that allow them to work with the code, but not make changes to it. While Microsoft chief executive Steve Ballmer has suggested over the past two years that the company was interested in making the Windows source code more freely available, there was little evidence that Microsoft actually was interested in doing so. "Microsoft is so security-conscious about letting the Windows source slip into anyone's hands" that a move to liberalise its source availability among customers is surprising, said Summit Strategies analyst Dwight Davis. Davis said that during the remedy phase of the Department of Justice's antitrust trial against the software giant, Microsoft fought suggestions that it be required to share Windows source code with any kind of neutral third-party licensing body. Microsoft is not going so far as to allow its customers to tamper with the Windows source, Miller emphasised. By contrast, software that is licensed under the terms of the GNU General Public Licence may be altered by developers, as long as they agree to publish any changes before publicly distributing the modified source code. "We don't want to be in the situation that Linux is in, where there are more than 140 different distributions, leading to serious fragmentation," Miller said. Nonetheless, Miller said Microsoft has become proactive in talking to customers about the plusses and minuses of open source software. He said Microsoft is constantly evaluating the packaging, pricing, channel programs, methods of distribution and other factors that lead customers to select one software product over another. "Only a very small number of our customers want source code," Miller said, "but we've gotten a lot more aggressive in the past six months" about providing Microsoft's largest customers with source code, if they express an interest in having it. Miller said that Microsoft's expectation is that customers who find a bug or another change they would like to see made in the source would contact Microsoft for tweaks. Miller said that Microsoft and its customers have not found many other open source elements worthy of emulation. He said Microsoft believed its existing software development and testing paradigms served the company well. Miller added that Microsoft is moving to a subscription model, rather than to the open source business model of free software, supported by paid-for consulting services. Take me to the Linux Lounge Have your say instantly, and see what others have said. Click on the TalkBack button and go to the Linux lounge Or perhaps you'd rather chat about Microsoft Let the editors know what you think in the Mailroom. And read what others have said.