Microsoft Corp. said the Linux operating system and other freely distributed programs violate 235 of its patents, and it wants makers of such software to pay royalties.
The world's largest software maker would rather license its technology than litigate, Redmond, Wash.-based Microsoft said Monday in an e-mailed statement.
Microsoft had earlier said Linux and so-called open-source software violate its patents without detailing the claims. Last year it struck a deal with Novell Inc., the second-largest seller of Linux, in which both agreed not to sue each other's customers. Two weeks later Microsoft Chief Executive Steve Ballmer said Linux "uses our patented intellectual property."
Some of the patents that Microsoft claims have been violated relate to the Linux graphical design, e-mail, the operating system core and the Open Office word processing and spreadsheet programs that compete with Microsoft Office.
The agreement with Novell dulled a long-standing rivalry. At the same time it came under fire from open-source advocates such as the Free Software Foundation, which develops the General Public License, a popular open source license used for the core of the Linux operating system.
A new version of the license terms proposed by the group would prevent future deals of the kind struck between Microsoft and Novell, which also involved the companies agreeing to make their software interoperable.
Microsoft criticized the new version in its statement, saying it "attempts to tear down the bridge between proprietary and open-source software that Microsoft has worked to build with the industry and customers."
Microsoft and Novell's partnership has won customers such as Wal-Mart Stores Inc. and Credit Suisse Group.
Shares of Microsoft rose 8 cents to $30.97.