A major challenge to the principles of free software was thrown out of a German district court last week.
German DSL router vendor AVM had attempted to stop Cybits, which produces children's web filtering software, from modifying any part of the firmware used in its routers, including a key piece of Linux-based free software.
Both companies use the Linux kernel, which is licensed under the General Public License (GPL). In order for the Cybits filtering program to work, it needs to alter certain parts of this kernel, including removing some updates that were added by AVM. AVM claimed that changing the kernel infringed their copyright.
In its ruling the court apparently sided with Cybits, saying that users of embedded devices with pre-installed free software have the legal freedom to make, install, run and distribute modifications to this free software.
Harald Welte, who helped write the firewall code included in the Linux kernel, argued on behalf of Cybits. He also heads the GPL Violations Project, which enforces the public software licence. The GPL allows everyone to use, study, share and improve works that use it, but it also imposes those same conditions on any company using GPL software.
"I am extremely pleased that the court turned down any request by AVM to control any modification to the GPL licensed components of the Fritz!Box firmware. Enabling and encouraging everyone to innovate based on existing software and products is a key aspect of the free software movement," said Welte.
Other free software advocates s also welcomed the news. "Free software gives everybody the right to use, study, share and improve it. Nobody should be allowed to prevent others from executing those rights," said Matthias Kirschner, Free Software Foundation Europe's German coordinator.
The full written court ruling will be available in coming weeks, but the decision can be appealed by either party within one month.