Düsseldorf Court on the Use of Trade Marks for Open Source Software

For a while now, lawyers have been struggling with the relationship between (trade mark) protection of software names and Open Source licensing. Last month, the Higher Regional Court of Düsseldorf (Oberlandesgericht Düsseldorf) handed down an important decision that may shed some light on the intriguing issues linked to trademarking Open Source software. We publish this decision (the German original and an English translation) and explain what it is about.

Facts and procedure

Let’s begin with the facts (and some procedure): As so often the case in IP matters the decision was handed down in preliminary injunction proceedings. Thus, it is still possible that at some point we will hear of the matter again (that is, if the plaintiff decides to file a regular action). The plaintiff, DP GmbH (DP) is the owner of the community trade mark “Enigma” which is protected for operating systems, drivers, set-top-boxes, satellite receivers and digital TV receivers. Its sister company, DM GmbH (DM) distributes set top boxes, whose firmware is based on Linux. DM developed its own user interface, published it under the name “Enigma” and licensed it under the GNU General Public License, version 2 (GPLv2). Since 2006, DM has distributed a new version of this user interface, called “Enigma 2”. “Enigma” and “Enigma 2” are used by numerous manufacturers for their own set top boxes.

The defendant S GmbH (for convenience and legibility I ignore another company which acted as a third party intervener on the defendant’s side) distributes a set top box that uses “Enigma 2”. “Enigma 2” was used with certain adaptations to S’ hardware. S advertised its device with the words “fully equipped HDTV Tuner PVR with Linux Enigma 2 operating system”. The product description contained the following language: “400 MHz CPU + Linux OS Enigma 2 + Internal HDD (2.5/3.5) + Twin DVB-S2 Tuner + E-SATA/ 3 x USB, …”. Moreover, when a user clicked on “About”, a window popped up with information about the precise software status, including a reference to “Enigma”.

The plaintiff argued that the above-described infringed its community trade mark. The court of first instance agreed and ordered S to refrain from using “Enigma” in the course of trade for operating systems. S appealed the decision, and the case was brought before the Higher Regional Court of Düsseldorf (the same court that was responsible for another open source related trade mark decision in 2010). The judges of the appeals court reversed the lower court’s decision.

The ruling

Use as a trade mark and use as a work title

According to them, S had not used the term “Enigma” as a trade mark – as required by art. 9 para 1 b) of the Community Trade Mark Regulation (CTMR) – but only as a work title. Using “Enigma 2” as described above thus did not indicate the origin of the software. Rather, consumers understood this as a necessary identifier of the software itself.

The court continued that in any event, the way S had used the term “Enigma 2” would be permitted by art. 12 b) of the CTMR: The title “Enigma 2” was used by S in order to inform (potential) customers about the characteristics of their products. Moreover, as the software “Enigma”/”Enigma 2” was utilized by numerous companies under the license conditions of the GPLv2, the relevant public had gotten used to “Enigma” being the name of a certain software product associated with a wider range of sources.

Even if customers did not have this understanding of the term “Enigma”, the prerequisites of art. 12 b) of the CMTR would have been met, the court held. Under the GPLv2, S was allowed to reproduce the work called “Enigma”/”Enigma 2”. In such a case, S must also be permitted to identify this work, which can only be done by using its name. Here, the court used an interesting analogy to an older decision of the Federal Supreme Court (Bundesgerichtshof, BGH): In 2000, the BGH held that once a work had entered the public domain, anyone was permitted to use this work’s title, even if this title was registered as a trade mark. According to the Düsseldorf court, the situation is similar when a work may be used by anyone under a free license.

Use for modified software

If this were not interesting enough, we now get to the trickier stuff: the use of the software title for modified software versions. The court recognized that software may not be used on different types of hardware without being subject to some adaptations. Therefore, the use of its (trademarked) title should even be lawful when the program has been adjusted to the technical environment it is used in. Yet the judges went even one step further: Even making use of the software title for a program with certain new functions would be covered by art. 12 b) CTMR. This principle would at least apply, as long as the essential functions of the original software are sustained, and pre-existing third-party plug-ins still work with the software.

Importantly, the court emphasized that above-stated principles only apply so long as the user meets all the license conditions of the GPLv2. Otherwise, using the trademarked title would not be in accordance with honest practices in industrial or commercial matters.

Moreover, it should be noted that the ruling covers only the simple use of a trade mark as an indispensable identifier of the software used; therefore the principles above cannot justify any form of use going beyond the narrow scope described in the decision.


I think that the decision provides very valuable guidance for open source-related trade mark cases. To me, the principles developed by the court seem to be well balanced and to correctly reflect the technical realities of the production and marketing of devices with embedded software. Admittedly, some of the factors that the court deemed decisive appear to be vaguely defined; in particular, it will remain highly difficult to decide when modifications of the software will be OK, and when they will be too far-reaching for a legal use of a trademarked work title. However, this is nothing the court can be blamed for, as the case did not require further clarification of these issues.


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