Microsoft general counsel Brad Smith defended Microsoft patent agreements with Novell and a string of small Linux distributors at the Open Source Business Conference in San Francisco Tuesday, but urged a less abrasive relationship between open source code developers and his company.

Smith, who is the highest Microsoft executive to visit an open source conference, is a senor VP and corporate secretary as well as general counsel. Much open source code is running on the Windows platform and Microsoft, through its Feb. 21 interoperability pledge and other measures, is trying to convince developers that it can be viewed as an ally rather than an antagonist.

At one point, a questioner drew laughs when he pointed out the Microsoft CEO Steve Ballmer had once referred to open source as "a cancer," while chairman Bill Gates had referred to it as "Communism." "How does Microsoft collaborate with 'cancer' and 'Communism?'" he asked.

"I don't think you've heard Bill or Steve talking in those terms of late," he responded.

"You know, what we all do is software. Think how much more work we could do if we found a way to work together across the boundaries," he told attendees in a 30-minute talk that offered no new peace initiatives. It was Smith a year ago who told Fortune magazine that Microsoft had concluded Linux and other open source code infringed on 238 of its patents.

Smith defended the patent system, saying it was imperfect but the way U.S. software makers have traditionally defended their intellectual property. He made no new reference to alleged open source infringements and declined to repeat old ones. He said Microsoft wanted to sign patent agreements with as many entities as it could so that developers would be free to produce work without worrying about whether it infringed on some Microsoft patent.

"We live on both sides of the patent fence. We have more patent suits filed against us than any other company. We spend more money defending ourselves than any other company," he asserted. He reminded attendees that Microsoft paid $900 million to Sun Microsystems to end the outstanding patent and copyright disputes between them.

He said Microsoft reached an agreement with Novell in the fall of 2006 in order to free Novell's engineers to develop with Linux as they saw fit. He emphasized that Microsoft is willing to make its patent rights available cheaply to those who agree to negotiate for them. "We believe in building a bridge that allows different parts of the industry to participate." But with some Microsoft competitors and critics, "that is a hard bridge to build," he said with emphasis.

Andrew Updegrove, a partner in the law firm Gesmer Updegrove LLC, was a member of a panel following Smith's talk and asked, "Wouldn't it be a great step to assert that no patents will be used against Linux?"

Smith responded, "That would be saying, 'Hey, if you create the Linux kernel, you get a free pass.' You're not likely to hear that from us in the near future."

A questioner in the audience pointed out that Microsoft negotiated agreements with other corporate entities, but Linux had no such corporate representative, or patents with which to reach a cross-licensing agreement. Smith insisted such agreements had to be reached on a case-by-case basis and that meant dealing with another legal, usually corporate, entity.

James Bottomley, CTO of SteelEye Technology and a Linux kernel developer, asked Smith how Linux developers could ever reach an agreement with Microsoft on patents, when the open source GPL license grants rights to use software to all downstream users from the issuer.

"You've put your finger on one of the conundrums," agreed Smith. "We're a cathedral. A cathedral can do an agreement with another cathedral, but how does a cathedral do [an agreement with] a bazaar?"

Bottomley, after the exchange, said Microsoft wasn't winning hearts and minds of open source developers, even as it attempted to extend a peace-seeking hand. It's terms for agreement in the end "destroy the promise of open source," which is that the source code will be freely available for use and modification by end users.