Who Owns Linux? Kernel Copyright and Trademark

Who owns Linux: the short answer

Linus Torvalds created Linux, and in August 1991 he announced that he was developing the Linux kernel, but today no single person or company owns all of it. The answer to "who owns Linux" depends on which part you mean.

The code belongs to the people who wrote it. Each contributor keeps the copyright in their own work, and the whole kernel is licensed under the GNU General Public License (GPL) version 2 only. The name is different: "Linux" is a registered trademark of Linus Torvalds himself. The Linux Foundation is the exclusive licensee of that trademark, not its owner, and it does not decide which patches enter the kernel.

The sections below take each layer in order. First the code, then the name, then the Foundation. The last section covers the SCO lawsuits, which tested ownership claims about Linux in court.

Who holds the copyright in the Linux kernel code?

The Linux Foundation states it directly: "no single person or entity owns all the copyrights for the Linux kernel." It calls this "a distributed copyright ownership structure." In the most common model, it says, "contributors retain their copyright ownership", and that fact is recorded in the contributions themselves through the Developer Certificate of Origin (DCO) sign-off.

The kernel project's own pages point the same way. The legal page on kernel.org says distributed software "is copyrighted by their respective contributors". That page is a general disclaimer for everything kernel.org hosts, so it is not a statement about the kernel alone. The kernel developers' enforcement statement is more specific. It refers to "the separate copyright interests in the contributions made to our community."

One distinction matters here. The kernel's patch-submission guide explains how to sign off a patch, but it says nothing about who owns the copyright afterwards. The ownership statement comes from the Foundation. The sign-off is the mechanism the Foundation points to.

A practical result follows from this structure. Because no single entity holds all the copyrights, no single entity is in a position to relicense the whole kernel by itself.

What does the Signed-off-by line certify?

Every patch sent to the kernel carries a sign-off. The kernel's submitting-patches guide describes it as "a simple line at the end of the explanation for the patch". By adding it, the contributor certifies "that you wrote it or otherwise have the right to pass it on as an open-source patch." The rules being certified are the Developer's Certificate of Origin 1.1, which the guide prints in full.

The DCO opens with "By making a contribution to this project, I certify that:" and then lists four clauses, (a) to (d). Clause (a) covers the plain case: the contribution was created in whole or in part by the contributor, who has the right to submit it under the open source license indicated in the file. Clause (b) covers work based on earlier code that is under an appropriate open source license. Clause (c) covers a contribution passed on unchanged from another person who certified (a), (b) or (c).

Clause (d) is about the public record. The contributor agrees that the contribution is public and that "a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed". The guide also requires contributors to use "a known identity (sorry, no anonymous contributions.)"

Git writes the line itself. The guide says: "This will be done for you automatically if you use git commit -s." The commands below set an identity, make a signed-off commit, and print its message.

git config user.name "Ana Example"
git config user.email "ana@example.org"
git commit -s -m "docs: fix a typo in the README"
git log -1 --format=%B

The last line of the printed message reads Signed-off-by: Ana Example <ana@example.org>. Git builds it from the name and email set in the first two commands. The guide's own example uses the same shape, with the name Random J Developer.

When a patch passes through several hands, each person adds a line. The guide says these chains "should reflect the real route a patch took as it was propagated to the maintainers and ultimately to Linus".

The Linux Foundation's guidance on contribution mechanisms adds the legal framing. The DCO is "not a contract" and "not itself a license". It is a one-way statement by the contributor. The same page says "The Developer Certificate of Origin originated from the Linux kernel contributor community." The sign-off still certifies the right to submit when a coding assistant wrote part of the patch, and that is the question behind open source projects' policies on AI-assisted code.

Which licence covers the Linux kernel?

The kernel's top-level COPYING file names the licence. It says the kernel is provided "under the terms of the GNU General Public License version 2 only," with "an explicit syscall exception". It also says "All contributions to the Linux Kernel are subject to this COPYING file." Anyone can read the file's machine-readable tag:

curl -s https://raw.githubusercontent.com/torvalds/linux/master/COPYING | grep SPDX

The output is SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note. SPDX (Software Package Data Exchange) is a standard set of short licence names. The tag says "GPL-2.0", and the kernel's licence-rules document spells out what that means: "The Linux Kernel is provided under the terms of the GNU General Public License version 2 only (GPL-2.0)". In plain terms, the kernel is GPL-2.0-only.

The syscall note answers a question that every program running on Linux raises. A program talks to the kernel through system calls. The licence-rules document says "the syscall interface is a clear boundary, which does not extend the GPL requirements to any software" that uses it. So an application does not fall under the GPL just because it runs on Linux.

Code inside the kernel is a different matter. The enforcement statement says "Compliance with the reciprocal sharing obligations of GPL-2.0 is critical." For where those obligations came from, and how they differ from permissive licences, see the history of the GPL, MIT and Apache licences. For what the licence means for cost, see whether Linux is really free to use.

Who owns the Linux trademark?

The name is a separate piece of property from the code. The Linux Foundation's trademark page opens with the legal line: "Linux® is the registered trademark of Linus Torvalds in the U.S. and other countries." The Foundation describes itself as "the exclusive licensee of Linus Torvalds, owner of the mark on a world-wide basis."

The Foundation manages the mark through the Linux Mark Institute (LMI), which it administers. Under LMI's sublicensing program, "The Linux Foundation offers a free, perpetual, world-wide sublicense to approved sublicense applicants." In return, a sublicensee "must agree not to challenge Linus Torvalds' ownership of the Linux mark in any jurisdiction". The Foundation's separate trademark-usage page says use of the name "must be in accordance with the Linux Mark Institute's policy."

When does a product need a Linux trademark sublicence?

The Foundation's page gives a three-question test. Is the name a trademark? Does it contain "Linux"? Is it used for software-related goods or services? "If the answer to all three of the following questions is 'yes,' then you need to apply for a sublicense." If any answer is "no", no sublicence is needed.

Most everyday use falls outside the test. The page says "Fair uses of 'Linux' do not require you to obtain a sublicense," and that a journalist writing articles that include the term does not need one. It also says no sublicence is needed for a domain name that includes Linux, and it calls T-shirts and mugs "generally considered fair use."

A trademark also covers narrower ground than many people expect. In 2007, InformationWeek reported that Torvalds owns the Linux trademark and that "so does Rosch, a detergent company based in Switzerland", because "trademarks are granted on a much more narrow basis." That is a 2007 press report. Whether such a registration still exists would need a check in the Swiss trademark register.

When did the Linux Foundation form, and from what?

The Foundation came from a merger. In 2000, a consortium of companies including IBM, HP and Intel founded the Open Source Development Labs (OSDL). In 2007, the OSDL merged with the Free Standards Group to become the Linux Foundation. The Foundation describes itself as "a 501(c)(6) non-profit".

Who funds the Linux Foundation, and whom does it employ?

Member companies fund it. The Foundation writes about "the important role of the LF's company members in sponsoring open source projects and hiring developers." Its members page says members "help support the development of shared technology resources". It also notes that "key maintainers of LF's largest projects are not volunteers but full-time employees of member companies".

The Foundation pages cited here give no revenue breakdown and no fee table. Readers who want the numbers should go to the annual reports published on linuxfoundation.org, which are the primary record.

On people, the Foundation lists Linus Torvalds and Greg Kroah-Hartman as Fellows. Its biography of Torvalds says "Linus remains the ultimate authority on the new code incorporated into the standard Linux kernel." Its Fellows page says Kroah-Hartman continues his kernel maintainer work "while working in a fully neutral environment." Neither biography sets out employment terms.

What does the Linux Foundation not control?

It does not control which patches get merged. The kernel's process document is exact: "There is exactly one person who can merge patches into the mainline kernel repository: Linus Torvalds." Torvalds pulls from subsystem maintainers, and "as a general rule, Linus trusts the subsystem maintainers to not send bad patches upstream". The document calls those maintainers "the gatekeepers (in a loose way) for the portion of the kernel they manage".

New code enters during a merge window of about two weeks, which closes with the first release candidate, -rc1. Merge decisions in that process belong to Torvalds and the maintainers he pulls from. Torvalds holds a Fellow title at the Foundation, but his merge authority comes from the kernel's own process. For how that process grew from one developer's project, see the Linux kernel history timeline.

What did the SCO lawsuits claim, and how did they end?

The SCO Group's lawsuits tested ownership claims about the code in and around Linux in court. Two cases matter most: SCO against Novell, over who owned the UNIX copyrights, and SCO against IBM.

In the Novell case, the district court in Utah first gave summary judgment to Novell on copyright ownership. On 24 August 2009, the US Court of Appeals for the Tenth Circuit (No. 08-4217) reversed that part: "We affirm the judgment of the district court in part, reverse in part, and remand for trial on the remaining issues." The question of ownership went back for trial.

The Tenth Circuit's later ruling records the result: "On remand, after a two-week trial, a jury determined Novell owned the copyrights." The district judge also "concluded Novell retained rights in the licenses which included the right to prevent SCO from terminating a UNIX license issued before the transfer." SCO appealed again. On 30 August 2011, the Tenth Circuit (No. 10-4122) said "We affirm." That ruling is an unpublished order and judgment, which the court notes is not binding precedent. So the jury found that the UNIX copyrights in dispute belonged to Novell, not SCO.

In the IBM case, the Tenth Circuit's opinion records that SCO accused IBM of disclosing Santa Cruz's proprietary materials for inclusion in Linux. The court (No. 16-4040) filed its opinion on 30 October 2017 and an amended opinion on 2 January 2018. It held: "We REVERSE and REMAND the district court's summary judgment order on the misappropriation claim, and AFFIRM as to the remaining issues." One claim went back to the district court. The case is No. 2:03-CV-00294 in the US District Court for the District of Utah, and anyone who needs its final outcome should read that docket rather than a summary.

The background to these cases runs back through UNIX itself, which the history from UNIX to Linux covers. For how the GPL and the wider movement took shape around Linux, see the history of open source.

FAQ

Does Linus Torvalds own Linux?

Linus Torvalds owns the Linux trademark. The Linux Foundation's legal page says "Linux® is the registered trademark of Linus Torvalds in the U.S. and other countries." He does not own all of the code. The Foundation says no single person or entity owns all the copyrights for the Linux kernel, because contributors keep the copyright in their own work. He is, however, the one person who merges patches into the mainline kernel.

Does the Linux Foundation own the Linux kernel?

No. The Foundation itself says the kernel has a distributed copyright ownership structure, with no single owner. For the trademark, the Foundation is the exclusive licensee of Linus Torvalds, not the owner. It also does not merge code: the kernel's process document says only Linus Torvalds can merge patches into the mainline repository.

Do I need permission to use the name Linux?

Only when all three tests apply: the name is your own trademark, it contains "Linux", and it is used for software-related goods or services. In that case the Linux Mark Institute offers a free, perpetual, world-wide sublicence, and the sublicensee agrees not to challenge Torvalds' ownership. Fair uses, such as writing articles about Linux or a domain name that includes the word, do not need a sublicence.

Does software that runs on Linux have to be GPL?

No. The kernel is GPL version 2 only, with a syscall exception. The kernel's licence-rules document says the syscall interface is a clear boundary that does not extend the GPL requirements to software using it. Code that becomes part of the kernel is different, because the COPYING file says all contributions to the kernel are subject to it.

What did the SCO lawsuits claim, and who won?

SCO claimed ownership of UNIX copyrights and accused IBM of disclosing proprietary material for inclusion in Linux. In SCO against Novell, a jury found that Novell owned the copyrights, and the Tenth Circuit affirmed on 30 August 2011. In SCO against IBM, the Tenth Circuit's amended opinion of 2 January 2018 sent one misappropriation claim back to the Utah district court and affirmed the rest. The final outcome of that case is in the district court docket, No. 2:03-CV-00294.