In comments confirming the open-source community's suspicions, Microsoft Corp. CEO Steve Ballmer Thursday declared his belief that the Linux operating system infringes on Microsoft's intellectual property.

In a question-and-answer session after his keynote speech at the Professional Association for SQL Server (PASS) conference in Seattle, Ballmer said Microsoft was motivated to sign a deal with SUSE Linux distributor Novell Inc. earlier this month because Linux "uses our intellectual property" and Microsoft wanted to "get the appropriate economic return for our shareholders from our innovation."

The Nov. 2 deal involves an agreement by Novell and Microsoft to boost the interoperability of their competing software products. It also calls for Microsoft to pay Novell US$440 million for coupons entitling users to a year's worth of maintenance and support on SUSE Linux to its customers. In addition, Microsoft agreed to recommend SUSE software for Windows users looking to use Linux as well.

A key element of the agreement now appears to be Novell's $40 million payment to Microsoft in exchange for the latter company's pledge not to sue SUSE Linux users over possible patent violations. Also protected are individuals and noncommercial open-source developers who create code and contribute to the SUSE Linux distribution, as well as developers who are paid to create code that goes into the distribution.

Many open-source advocates criticized the deal, nevertheless. They argued that it was tantamount to an admission of patent violations by a key Linux supporter that bolstered Microsoft's case if it decided press its patent claims.

At the time, Microsoft officials, including Ballmer, were mum on whether the Linux kernel, which is governed by the General Public License and takes contributions from programmers all around the world, violated Microsoft's patents.

Ballmer was more open Thursday.

"Novell pays us some money for the right to tell customers that anybody who uses SUSE Linux is appropriately covered," Ballmer said. This "is important to us, because [otherwise] we believe every Linux customer basically has an undisclosed balance-sheet liability."

"My reaction is that so far, what he [Ballmer] said is just more FUD [fear, uncertainty and doubt]," said Pamela Jones, editor of the Groklaw.net blog, which tracks legal issues in the open-source community. "Let him sue if he thinks he has a valid claim, and we'll see how well his customers like it."

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