The legal war between SCO and IBM has taken another step, with SCO asserting that IBM does not have the right to enforce the GPL (GNU General Public License) software licence that governs the Linux operating system.

"The GPL is selectively enforced by the Free Software Foundation such that the enforcement of the GPL by IBM or others is waived," SCO claimed in papers filed last week with the US District Court in Utah. "The Free Software Foundation is the only entity that can enforce the GPL so, in effect, IBM is barred from trying to enforce the GPL with SCO," wrote Blake Stowell, a SCO spokesman. SCO's filings also assert that "the GPL violates the US Constitution, together with copyright, antitrust and export control laws."

The filings were made in response to a countersuit brought against SCO by IBM last August, which alleged that SCO had violated the GPL and a number of IBM's software patents.

SCO and IBM have been engaged in a legal dispute over Big Blue's contributions to Linux since SCO sued the computer giant in March, alleging that IBM had inappropriately contributed code to the open source OS in an effort to enhance its Linux server business.

A lawyer representing the Free Software Foundation (FSF) disputed SCO's claims that the FSF is the only organisation with the necessary legal standing to launch a GPL-based lawsuit. Since IBM holds the copyright to much of the Linux kernel that's distributed under the GPL license, it has every right to enforce the GPL, he argued.

"The proper enforcer of a copyright is the copyright holder," said Eben Moglen, general counsel for the FSF. "IBM says, 'You're using a copyrighted work of ours in a fashion which is prohibited by the Copyright Act, and you're doing so without our permission. You owe us damages and you must stop.'" If the GPL is not a valid licence, Moglen reasoned, then SCO itself does not have the right to redistribute Linux -- something it has done for years. "If SCO says the GPL isn't valid permission, then they have no valid permission," he said. "Redistributing copyrighted works without permission, we are told by the RIAA (Recording Industry Association of America) and MPAA (Motion Picture Association of America) every day, is stealing."

Related

One intellectual property lawyer not connected with the case agreed with Moglen's assessment. "I come down with Eben on this one," said David Byer, a partner with the Patent and Intellectual Property Practice Group at Testa, Hurwitz & Thibeault LLP. "This really is a matter of a third party adopting the terms of the FSF," he said. "The fact that (IBM) adopted the FSF form doesn't mean that they can't enforce their rights." Byer likened the GPL to the standard owner-contractor agreements created by the American Institute of Architects. Just because a home builder uses one of the Institute's forms does not mean that he gives up the right to sue in a contract dispute, Byer said. Similarly, IBM has not given up its right to sue SCO just by using an FSF licence, he said.

The court fillings also disputed IBM's claims that SCO had violated IBM's software patents. "If we're in violation of them, then just about every other vendor in the entire software industry is in violation of them," SCO's Stowell said in an interview. "What they're claiming is something that is a common practice within the software industry."

The fact that IBM's software patents may be wide-reaching, however, does not mean that they are unenforceable, Bayer said. "Arguing that (a patent) covers too many people isn't an effective defence," he said.