I am looking for an open source license that strictly matches the following criteria, could anyone suggest any?


  1. Rename the project
  2. Disclose the source
  3. Include the original license (also cannot choose any later version of license)


  1. Hold authors liable (including warranty)
  2. Sublicense
  3. Use project name as trademark
  4. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission
  5. Register a software patent with the source code
  • What do you mean by "cannot use trademark"? Do you mean that nobody should be able to register the project name as a trademark, or nobody should be able to use other trademarks in any derivative work? Or do you mean what you wrote in brackets (no implied or express claims of endorsement) and you're not actually worried about trademarks? Or something else?
    – MadHatter
    Commented Sep 23, 2023 at 6:17
  • @MadHatter I have edited the point to only include what was inside the bracket. Thanks
    – Anm
    Commented Sep 23, 2023 at 6:21
  • @MadHatter Hi, I have decided to include both the first and last clause of your comment after some thought (cannot use project name as trademark and what I wrote in brackets) and edited the post to reflect the same. Apoligies
    – Anm
    Commented Sep 23, 2023 at 6:34
  • 1
    (Obligatory: I am not a lawyer and this is not legal advice.) The best way to prevent people from using your project's name as a trademark is to use the project's name as a trademark yourself, and defend the trademark by normal processes (any combination of: 1) hire lawyers to send scary letters; 2) hire lawyers to sue people; 3) register the trademark, so that you have the right to use ® rather than ™). This should also incidentally end up requiring them to rename their fork. Commented Sep 23, 2023 at 23:13
  • (Some licenses state that they do not grant trademark rights, but that is not the same thing as explicitly reserving them.) Commented Sep 23, 2023 at 23:18

1 Answer 1


Firstly, copyright, trademark, and patent issues are all separate things, with separate processes and applicable bodies of law. I say this to clarify why it's a bad idea to try to handle, say, trademark issues in a copyright licence, and why it works much better to keep them separate.

A strong copyleft licence, such as GPLv3, will do most of what you want, and what it can't do is better done in parallel (see above). Specifically, it will do "must" 2 and 3, and "must not" 1 and 2.

"Must not" 4 does not need to be explicitly prevented, as it would constitute misrepresentation and is generally actionable anyway. If you feel strongly about this, a GPLv3 s7d restriction may be specified.

"Must not" 5 is achieved by the simple business of publishing your source code. At that point the source serves as prior art, which will prevent the issue of (in a perfect world) or can be used later to invalidate (in this world) any patent on a patentable concept expressed in the source code.

"Must" 1 and "must not" 3 are best done with a defensive trademark registration, and a separate trademark policy denying use rights to variants of the code; this approach is far from unknown (example) in the free software world, though not universally loved. A longer exposition of this idea, and a clarification of why it's not a good idea to try to do this in the copyright licence, can be found here.

  • What is a "GPLv3 s7d" and how can I specify it?
    – Anm
    Commented Sep 23, 2023 at 8:49
  • 2
    Follow the link to the GPL, and read section 7, clause d, to find out what it is. As 7 says, "If you add terms to a covered work in accord with this section, you must place, in the relevant source files, a statement of the additional terms that apply to those files, or a notice indicating where to find the applicable terms." so to apply it either note that a s7d restriction applies to the source code in the header of every source file where the GPL is mentioned as the applicable licence, or instead at the same place reproduce the text of s7d, or the text of your "must not" 4.
    – MadHatter
    Commented Sep 23, 2023 at 9:10
  • Thank you. One more thing, for the last paragraph of your answer I was perhaps looking for something like clause 1 and 2 of the Zlib-Libpng License (directory.fsf.org/wiki/License:Zlib), although it does not match other criteria I was looking for. Is there another license that specifies the same and matches other criteria?
    – Anm
    Commented Sep 23, 2023 at 10:55
  • 1
    @Anm Those zlib terms are also allowable section-7 restrictions under the GPLv3 (see Why is the zlib license GPL-compatible?). You can add those terms in the same way as you add the 7(d) term.
    – apsillers
    Commented Sep 23, 2023 at 14:22
  • 3
    @Bergi, the GPL includes a patent licence for that patent you just obtained. Commented Sep 23, 2023 at 18:29

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