Linus Torvalds is probably one of the persons that cannot be overestimated in their influence. It is not just the technical expertise and high quality software he delivers. The idea of Open Source is basically mingled to him. He will enter into world history chronicles due to his presents to the mankind, that he enabled a myriad of other technologies, products and wealth by enabling others. He showed the way to go. Other famous tech people like Gates or Bezos will remain in memory as well for some time, before falling into oblivion. But in their case more for their fabulous wealth they brutally enforced by hindering others.
As he explains disenchanted in his biography-style book "Just for Fun - The story of an accidental revolutionary", even though he promoted the Open Source idea courageously, at some point there seems to be no way around Intellectual Property. That is why we see him as the registered Trademark owner for "Linux" as individual kind of mark at the European Intellectual Property Office (EUIPO) . Trademarks are extendable indefinetely (Art. 53 EUTM) . This TM has an application date from the 16th of June 1998. If not extended, it will expire in 2028 according to the EUTM entry. Surprisingly, the registration date is only in 2006, almost 8 years later. It is a word type TM which is filed under Nice classifications 9, 16 and 42. As each TM application needs a secondary language, they selected German (de). Further, an EUTM application to the EUIPO requires an EU representative as stated by Art. 119 (2) and Art. 120 (1) EUTM . Here, a Swedisch association called VALEA AB is the legal contact point to the "LINUX" EUTM. As the period for the EUTM is 10 years (Art. 52 EUTM) , there were two renewals in 2008 and in 2018. A less intuitive term used in TM registration is "Acquired distinctiveness". Here it is "false". This means it did not become distinctive by its bare name to the public. So that even in the theoretical case that it would be non-distinctive according to Art. 7(1b) EUTM, descriptive Art. 7(1c) EUTM or a generic sign Art. 7(1d) EUTM it could become distinctive by its acquired distinctiveness through the use, fall under Art. 7(3) EUTM and be able to register.
When it comes to Linux, one thinks of Open Source. But this terminology is not mutually exclusive with all IP rights. That is why we can see clear statements about Linux Foundation's Trademark usage policy and how to correctly use their logo regarding Kubernetes. They refer to not change colors, some parts of the inherent design or any scaling operation on it. There are more Open Source and Linux related registrations to be discovered. So besides their own Linux Foundation EUTM they registered 8 EUTMs related to Kubernetes, visible on TMView . TMView is the EUIPO's online service to fullfill their public mandate demonstrating registered European Union Trademarks (EUTMs). It is basically a web tool to filter and present their TM database. But not only theirs, cause there are TMs from offices all around the world within that single tool. In addition to all offical EU languages, some other can be selected as well.
The Linux Foundation registered 3 word marks, namely "KUBERNETES", "KUBERNETES DAY" and "CERTIFIED KUBERNETES". The latter has an additional graphic representation. Their 4 Kubernetes related certifications "Kubernetes Associate", "Kubernetes Administrator", "Kubernetes Security Specialist" and "Kubernetes Developer" are listed with their corresponding logos as figurative TM. Those 4 have been registered on the same day the 12th of July 2022 under the Goods and Services (GS) category 41 according to the Nice classification. This category ID is referrring to "Education; Providing of training; Entertainment; Sporting and cultural activities". The same category holds for the word mark "KUBERNETES DAY". Whereas their oldest TM, the word mark "KUBERNETES", which was registered on the 5th of March 2015 is registered as GS category 9 "Scientific, research, navigation, surveying, photographic, cinematographic, audiovisual, optical, weighing, measuring, signalling, detecting, testing, inspecting, life-saving and teaching apparatus and instruments; Apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling the distribution or use of electricity; Apparatus and instruments for recording, transmitting, reproducing or processing sound, images or data; Recorded and downloadable media, computer software, blank digital or analogue recording and storage media; Mechanisms for coin-operated apparatus; Cash registers, calculating devices; Computers and computer peripheral devices; Diving suits, divers' masks, ear plugs for divers, nose clips for divers and swimmers, gloves for divers, breathing apparatus for underwater swimming; Fire-extinguishing apparatus".
What this shows is, that there is a significant difference between the different types of IP rights and how law is related to engineering. The Trademark approach does not interefere with noble aims of Open Source. Historically known, Software, but as much as possible any technology in general as Open Source, enables further development, innovation, modifications and in the long run security, compared to Closed Source. There is a clear benefit from Open Source. Here the Linux Foundation is actually comercially using those figurative marks and their popularity to sell their great knowledge on some technologies, in that case Kubernetes. They have high trust by developers and industry. The legal backing of their logo and name by authorities through that registration prohibits others to gain from their efforts to create that trust level. It is clearly different to patent, as the technology is still free to use by anybody. But third parties are safer from logo falsifiers which want to profit from one parties effort and the other parties unawareness. Unawareness of possibly falsified but similar logo and organization name. Anybody could call their class Certified Kubernetes but not delivering the expected content. Users would not buy those products anymore as there would be no mechanism that would give some level of guaranteed quality represented through the TM. Without that legal tool of TM, the economic market would be damaged in the long run due to the lack of trust.