The District Court of Hamburg, Germany, recently had the opportunity to review the conditions governing the use of Open Source software. In a decision that bolsters the enforceability of open source software licenses, the district court confirmed that the defendant had lost its right to use the software licensed under the General Public License (GPLv2) when it failed to fully reveal the underlying source code. The court rejected the defense argument that requiring the defendant company to comply with the conditions of the GPLv2 was unreasonable (decision of 14. June 2013, file no. 308 O 10/13, available in German here).

Background of the infringing software use

The plaintiff is the sole owner of the right to use the software “netfilter/iptables”, which he distributes to the general public for free as Open Source software under the GPLv2. One of the conditions for the use of software licensed under the GPLv2 is that the source code must be fully laid out by licensees upon further distribution of the software.

The defendant company Fantec GmbH markets electronic goods, among them a media player which contains the program “netfilter/iptables.” In 2010, the defendant had already failed to fully disclose the source code of that Open Source software and had submitted a cease and desist undertaking, including a contractual penalty payment in the event of future infringements.

In 2012, the plaintiff sent a further cease-and-desist letter to the defendant for its failure to fully lay out the source code. The defendant complied with the cease-and-desist request but refused to pay the contractual penalty and the plaintiff’s legal costs. In the court action the plaintiff brought before the District Court of Hamburg, the defendant argued that its Chinese contractor had guaranteed that the source code was complete. A comprehensive and effective control of the source code could only be performed by the respective author of the software and could not reasonably be demanded by future distributors. In particular, the defendant had informed itself about options for controlling the source code and had allegedly been told that despite significant costs, such a control could not assume any guarantees for completeness and correctness.

The decision of the District Court of Hamburg

The District Court fully granted the plaintiff’s claims. The judges held that the defendant had acted at least negligently when it failed to fully lay out the source code and was therefore in violation of GPLv2. The defendant had consequently lost its rights under the GPLv2 to use the plaintiff’s software. The court barred the defendant from relying on claims of completeness made by third parties. According to the court, as manufacturer and distributor the defendant had the duty to ensure compliance with the terms of use for the software used in its electronic goods. The defendant should himself have ensured compliance through a suitable control of the software, even if costly.


Most electronic goods nowadays use multiple Open Source software components. Often, these software programs are licensed under the GPLv2. Other licenses, such as the Apache License 2.0, the Mozilla Public License 2.0 and the Lesser General Public License (LGPL) are also widely used. All of these licenses request that the source code be fully revealed upon further distribution. Electronics manufacturers are thus under the obligation to ensure compliance with all of the licenses they make use of in order to benefit from the free use of the Open Source software programs in their own commercial interest. Particularly the obligation to always lay out the current version of the complete source code used in an electronic product carries the risk of errors. Various service offerors have therefore specialized in checking the source code of Open Source software. Despite the burdens this may place on manufacturers, the court was right in refusing to submit the terms of the GPL to some form of reasonability test, as the defendant had argued. A company seeking commercial benefit from the free use of an Open Source software program must in turn honor the particular conditions attached to such use and make its source code fully available, ensuring continued free use for everyone. You can find further information about Free and Open Source software on the website of the Free Software Foundation Europe.