Harald Welte said the companies have embedded Linux in their products but haven't released the underlying source code, as required by the General Public License, or GPL, that governs the operating system. He tried to notify 13 companies of his complaint at the sprawling trade show, but three companies refused to accept it, he said in an e-mail interview.
Most of the CeBit products he thinks violate the GPL are networking equipment, he said. In his general work, he's also found violations in set-top boxes, vehicle navigation systems and special-purpose software.
Much enforcement of the GPL's terms comes from the Free Software Foundation, an organization run by original GPL author Richard Stallman. But Welte, who has wanted GPL violations to be fixed more quickly and publicly, has strong enforcement credentials.
Welte is an author of networking software called netfilter/iptables that's covered by GPL. But he spends about a quarter of his time working on the GPL Violations Project.
The project is a "one-man show," but Welte has been a dogged fighter for his beliefs; he said he's settled more than 25 cases so far, and he's won two rounds in a court case against one company, Sitecom.
Open-source software, which introduces somewhat alien concepts such as sharing and cooperation, has at times been hard for the largely proprietary computing industry to swallow. Although the success of projects such as Linux, Apache and Firefox have made open-source software more mainstream, Welte believes much more education still is ahead.
"The ultimate goal is to raise awareness that the GPL is not public domain, but a copyright license," Welte said. "Instead of paying license fees, you provide a copy of the source code and pass the license to your users."
The GPL, a widely used 1991 legal framework now being modernized, permits anyone to use, modify and distribute a program. However, it also requires those who distribute the software to provide its underlying source code.
In some cases, the companies do try to supply the source code, but fall short of requirements, Welte said. "At least until three days ago when I checked last, this source code was either corrupted, incomplete or didn't correspond to the latest firmware versions," he said. Firmware is software embedded in products such as network cards or networking equipment.
In Motorola's case, Welte said, the company violates the GPL terms with its WA840G wireless network access point.
Motorola spokesman Paul Alfieri didn't have information specific to Welte's concerns, but said the company will correct any problems if those concerns are valid.
"If there is a question, we'll most certainly rectify it and it was most certainly an oversight," Alfieri said on Tuesday. "We use a lot of open-source stuff in our wireless and mobile products."
Indeed, Motorola ships Linux-based mobile phones, and it sold embedded Linux programming tools through its Metrowerks division, now part of spinoff Freescale Semiconductor.
Another company Welte targeted was Acer for its GW-300 and WLAN-G-RU2 wireless networking products. Acer didn't immediately respond to requests for comment.
Looking for clues
Welte finds evidence of GPL software by looking at software through a reverse-engineering process, not an easy task given that the software is in a form designed for consumption by a computer, not a human.
"This can sometimes be very lengthy and is probably for me something like crossword puzzles for other people," Welte said. "You basically sit down with a hex editor and try to figure out the format of the file and search for well-known signatures."
Companies that Welte said have met his demands include Belkin, Fujitsu-Siemens, U.S. Robotics, D-Link and Siemens.
The task isn't easy, Welte said.
"It's not sufficient if they just put the source code somewhere online. They actually need to educate their customers about their rights by providing a copy of the GPL license for both the physical products and for their downloads," Welte said.
Even if Welte gets his way with the CeBit attendees, it appears there's a new crop of violators on the way.
"There's a current indication that storage arrays and VoIP (voice over Internet Protocol) phones are going to be the next big product area, unless the vendors have already learned how to deal with the GPL--which I hope, but doubt," Welte said.
