The Free Software Foundation has harshly criticised a legal attack by the SCO Group against the licence that covers much open-source software, calling the argument "arrant, unprofessional nonsense".
Last week, SCO attorney Mark Heise revealed in comments to The Wall Street Journal that the company is planning to argue in court that the GNU General Public License (GPL), which covers Linux and related software, is invalid. The strategy is part of SCO's $3bn (£1.9bn) lawsuit against IBM, alleging that IBM committed trade-secret theft and breach of contract for allegedly copying proprietary Unix source code into its Linux-based products.
In a response published on Monday, Eben Moglen, a Columbia law professor and the attorney for the Free Software Foundation, which enforces the GPL, admitted that success by SCO would destroy the legal foundation for the GPL. However, he wrote, SCO's argument would also invalidate every other open-source licence, as well as Microsoft's Shared Source licence and its method of distributing the Windows operating system.
"Naturally, one would expect SCO to bring forward the best possible arguments against the GPL and its application to the current situation," Moglen wrote. "But there aren't any best arguments; there aren't even any good arguments, and what SCO's lawyer actually said was arrant, unprofessional nonsense."
SCO will argue that the GPL's provisions allowing unlimited copying and modification are not compatible with US copyright law, which allows software buyers to make only a single copy, according to the report. Heise said the GPL "is pre-empted by copyright law".
This interpretation is "utterly bogus", according to Moglen, saying it seems to be based on a misreading of section 117 of the US Copyright Act, which allows copies to be made of a copyrighted work without a licence, under certain circumstances. It does not place a limit on what copyright owners may permit through their licences, Moglen said.
Such an interpretation "would... eliminate Microsoft's method for the distribution of the Windows operating system, which is pre-loaded by hard drive manufacturers onto disk drives they deliver by the hundreds of thousands to PC manufacturers," he noted.
However, SCO's strategy may, in fact, be good news for the open-source software community, Moglen said, since, "it shows that SCO has no defence whatever against the GPL."
Broadly speaking, the GPL allows anyone to modify and redistribute a piece of software covered by the licence, as long as the modified code is returned to the developer community. The licence also requires that software incorporating GPL-covered code must itself be placed under the GPL, a provision that led a Microsoft executive to compare the GPL to an "un-American cancer" .
Heise's remarks echo the comments of SCO chief executive Darl McBride during a recent teleconference, in which he announced a set of licence fees that companies using Linux could pay if they wanted to avoid legal action by SCO.
McBride was unusually blunt in attacking open-source software, saying the GPL is fundamentally flawed from a business and legal perspective. "At issue here is more than just SCO and Red Hat," McBride said. "What is at issue here is whether intellectual property rights will have any value in the age of the Internet."
This week at SCO's annual user and developer conference, Chris Sontag, head of the company's SCOsource effort to extract more revenue from its Unix intellectual property, showed slides of the code allegedly copied from Unix to Linux.
Much of the Unix code in the slides was obscured, because the company wants to keep its intellectual property under wraps, but SCO is allowing people who want to see a more extensive side-by-side comparison during the conference to do so if they sign a nondisclosure agreement.
CNET News.com's Matt Hines and Lisa Bowman contributed to this report.