GPL gains clout in German legal case

The case involves netfilter/iptables, open-source networking software for tasks such as firewalls for protecting a network from unwanted traffic. Harald Welte, one of the main netfilter authors, sued a Dutch company, Sitecom, alleging it used the software in a wireless network product without abiding by the terms of the General Public License (GPL).

In April, a three-judge panel in a Munich court granted Welte's request for a preliminary injunction to stop distribution of the product without complying with the GPL. Specifically, the court forbade Sitecom's German subsidiary from distributing the netfilter software without attaching the GPL text and the netfilter source code free of royalties.

In a statement Wednesday, Sitecom Chief Executive Pim Schoenenberger said the company now complies with the GPL and is seeking the approval of the netfilter programmers. But the case has broader ramifications for a software industry increasingly dependent on the GPL.

"This would be the first reported decision I'm aware of that interprets the GPL," said Brian Kelly, an intellectual-property attorney with Manatt, Phelps & Phillips. "Case law interpreting the GPL is both inevitable and useful, because parties are going to end up fighting over ambiguities in the license."

The decision lends weight to the license, said John Ferrell of law firm Carr & Ferrell. "This preliminary German decision reinforces the essential obligations of the GPL by requiring that if you adopt and distribute GPL code, you must include the GPL license terms and provide source code to users," he said.

Boosting GPL compliance
The decision also could help Welte's efforts to track down GPL violators. He said he receives many reports of alleged violations because he has actively pursued several cases. He claims to have coaxed Allnet, Fujitsu-Siemens, Securepoint, Belkin and Asus into GPL compliance with their wireless networking products.

"So far, I know of about 170 devices that violate the GPL," including set-top boxes, DVD players and laser printers, Welte said, but he declined to say which ones "for strategic reasons." In any case, he can't take legal action in most of those cases because the devices don't use the netfilter code to which he holds copyright.

A decision in Germany isn't directly relevant to cases in the United States, but because the countries' copyright and contracts laws are similar, "so far, this case is really good news for the world GPL community," Ferrell said.

The GPL is the subject of increasing scrutiny for several reasons. For one thing, Linux is growing more popular--sales of servers using the open-source operating system grew 63 percent to $960 million in the fourth quarter of 2003, according to IDC. Blossoming alongside Linux are other GPL-covered projects, including software for word processing, network adapters and Windows file sharing.

For another, the GPL is an issue in the SCO Group's legal actions against Linux users and Linux advocate IBM. IBM has alleged GPL violations in its countersuit against SCO, while SCO has argued the license "violates the U.S. Constitution, together with copyright, antitrust and export control laws."

The GPL's origins
Free Software Foundation founder Richard Stallman created the GPL as a legal foundation for the Gnu's Not Unix (GNU) project, launched in 1984 to create a clone of the Unix operating system. The GPL permits anyone to see, modify and redistribute software as long as those changes are made public.

Eben Moglen, the attorney and Columbia Law School professor who represents the Free Software Foundation, has enforced the GPL several times, but those cases haven't produced a legal ruling.

One close call was a 2002 suit by open-source database seller MySQL, which unsuccessfully invoked the GPL in a suit against Progress Software, whose NuSphere subsidiary had incorporated the MySQL database into a product called Gemini. The companies eventually settled the case out of court.

"With respect to the General Public License, MySQL has not demonstrated a substantial likelihood of success on the merits of irreparable harm," said District Judge Patti Saris of the U.S. District Court in Massachusetts. "Affidavits submitted by the parties' experts raise a factual dispute concerning whether the Gemini program is a derivative or an independent and separate work under GPL Section 2. After hearing, MySQL seems to have the better argument here, but the matter is one of fair dispute."

One tricky part of the GPL is the "linking" question: How tightly coupled may a proprietary software package be with GPL-covered software? If a programmer wants to include GPL-covered software as part of a larger program, the GPL requires that the larger program also be released under the GPL--an effect some have termed the "viral" nature of the GPL.

But things aren't as clear when there's a looser link between the two bodies of software.

"There are a variety of ambiguities that the legal community is struggling with--primarily the linking issue," Kelly said.

Another part of the license governs situations in which a company is selling a product that includes GPL-covered software in an "executable" form--the instructions a computer, not a human programmer, understands. The GPL permits a company to sell the product with the executable software if is accompanied by the software's underlying source code or a written offer to provide that source code.

It is this provision that appears to have triggered Welte's action.

Sitecom and netfilter
Welte said he has spent weeks looking for uses of the netfilter software. To do so, he downloaded numerous products' "firmware"--the software that's loaded into the devices' memory--and examined it for telltale signatures.

As soon as he found the violation, in March 2003, he notified his attorney, Till Jaeger, who sent Sitecom a warning letter and a declaration promising to stop its practice. Sitecom, unlike several vendors Welte has pursued, didn't sign the letter, Welte said.

For its part, Sitecom said it took actions to comply but couldn't sign the declaration.

"As soon as Sitecom became aware of the issue, it immediately affirmed its cooperation in wanting to comply with the conditions of the GNU General Public License. By now all terms and conditions and requirements have been dealt with, and Sitecom now conforms to the GNU General Public License and are now awaiting their official approval," CEO Schoenenberger said in a statement.

"The reason that Sitecom did not want to sign the proposed declaration was simply because it was phrased, as presented initially to Sitecom, as an admission of guilt on Sitecom's part and that Sitecom was liable for unlimited costs. Naturally we were unable to sign that," Schoenenberger said.

Welte still isn't satisfied. "The source code they published on their Web site is still incomplete," he said.

Welte's success with netfilter, though limited, still is significant, said Mark Koehn, an attorney with Shaw Pittman.

"A determination on whether the GPL applies to particular software must be made on a case-by-case basis," Koehn said. "Nonetheless, it is a very important development for GPL proponents who, before this decision, could not point to a court decision enforcing the GPL."