Yzena Open License

A permissive license that is readable and thorough.

Yzena Open License 0.1

Version 0.1

This license is a draft. Do not use.


This license gives users as much permission to work with this software as possible, while protecting contributors from liability.


In order to receive this license, you must agree to its rules. The rules of this license are both obligations under that agreement and conditions to your license. You must not do anything with this software that triggers a rule that you cannot or will not follow.

Source Code

In this license, the phrase “source code” includes the original copyrighted material of any software.

This Software

In this license, the phrase “this software” includes the source code licensed under this license. It also includes the output of any execution of any algorithm that uses all or part of this software as all or part of its input, but only if the output itself is software.

Each contributor licenses you to do everything with this software that would otherwise infringe that contributor’s copyright in it, except anything that would break any rule of this license.


You must ensure that everyone who gets a copy of any part of this software from you also gets the text of this license.


If the source code includes a file named CREDITS.md or NOTICE.md, then you must ensure that everyone who gets a copy of any part of this software from you, with or without changes, also gets the verbatim text of that file.


This License does not grant you any rights to the names, trademarks, service marks, or logos of any contributors.


You cannot initiate any patent litigation claiming that this software infringes any patent, directly or indirectly.


If any contributor notifies you in writing that you have not complied with Notices, Credits, Trademarks, and/or Litigation, you can keep your license by taking all practical steps to comply within 30 days after the notice. If you do not do so, your license ends immediately after the 30 days.


Each contributor licenses you to do everything with this software that would otherwise infringe any patent claims they can license or become able to license.


No contributor can revoke this license from you unless you do not follow its rules.

No Liability

As far as the law allows, this software comes as is, without any warranty or condition, and no contributor will be liable to anyone for any damages related to this software or this license, under any kind of legal claim.

Yzena Open License Frequently Asked Questions

  1. What is the Yzena Open License (YOL)?

    It is a permissive Open Source license close in spirit to the Apache 2.0.

  2. Who are you? And are you a lawyer?

    I am Gavin D. Howard, founder of Yzena.

    No, I am not a lawyer, but most of this license is taken from the Blue Oak Model License 1.0.0 (BOML), which was written by lawyers.

  3. Why did you choose the BOML to start with?

    See here, here, here, and here. Basically, the BOML is supposed to be a model for how licenses should be.

  4. What is the list of changes you made from the BOML?

    These are the changes I made:

  5. If you mostly copied the BOML, why shouldn’t I just use that one?

    You actually should; if all you need is a typical permissive license, then yes, you should use the BOML.

    However, there are three clauses in the YOL that are not in the BOML:

    If you need those three things in a license, then the YOL might work for you. Be sure to consult with your lawyer first.

    In fact, those last two clauses are what makes the YOL closer to the Apache 2.0 than the MIT/BSD licenses.

  6. Why do you use such vague language and don’t define some of your terms?

    Because the BOML doesn’t. See more here and here. I decided that if lawyers did it, it should be fine.

  7. Your Credits section doesn’t actually require giving credit.

    No, it doesn’t. But it does require providing the verbatim text of the CREDITS.md or NOTICE.md file, and I assumed that the contributors would add whatever credits they wanted in there.

  8. You also don’t require giving a link to the original project, if someone makes changes and relicenses the code.

    No, but I also assumed that the original contributors would put that information in the CREDITS.md or NOTICE.md, and that text must be provided verbatim.

    That assumption simplified the license, which makes things easier on contributors and users.

  9. Why does the Credits section require that the file be in the Markdown format?

    It made it easier to write the license and will make it easier to comply with the license.

    More concretely, the Apache 2.0 License uses the phrase “NOTICE file.” I decided to avoid that awkward language.

    And while I could have chosen any file format, Markdown is text, easily readable, well-supported (with ways to convert it), and should have all of the features that would be needed for such a file.

  10. The Credits section says that it is required to provide the verbatim text of the CREDITS.md or NOTICE.md file. Why didn’t you just require people to provide the file?

    Because if someone makes changes to the software, I wanted them to be able to add their own credits to the CREDITS.md or NOTICE.md file, which they can do by adding theirs at the bottom or the top of the original, since the verbatim text of the original will still be intact.

  11. What do you suggest putting in the CREDITS.md or NOTICE.md file?

    I suggest adding these things:

    • The name of the original software.
    • The original copyrights on the software.
    • A link to the original code/repository.
    • A link to the Yzena Open License to inform users that it is possible to get the original under this license if they wish.
    • The (preferred) names of all contributors that want credit.

    I also suggest having a paragraph that says:

    All files in this repository are under the Yzena Open License, Version 0.1, and all such files are considered part of the “source code” as defined by that license.

    In addition, if there are files in the repository that used to be under any licenses other than the YOL, then I suggest listing all such files, along with their respective former licenses and copyrights, as required by their former licenses, but to also make clear that the files have been relicensed.

  12. The previous question implies that everything in a repository should be under the YOL. What if there is code that is under other licenses?

    Such code should be relicensed, if possible. This is possible with permissive licenses.

    If it is not possible, then such code should not be integrated into the repository.

  13. Does this mean that any code under the GPL family of licenses should not be integrated into a repository under the YOL?


  14. Why do you care about patents and trademarks?

    Because I want to be able to make a business based on Open Source software, and I do not want to have to worry about losing trademarks or possibly getting sued for patent infringement.

    Also, software patents are, in my opinion, illegal because you can’t patent algorithms. They have also never been used for actual innovation, which makes them useless.

  15. What’s with the weird definition for “this software”?

    GitHub Copilot. I want the YOL to poison the well for machine learning like that.

    The reason is that GitHub is arguing that using FOSS code in Copilot is fair use because using data for training a machine learning algorithm has been labelled as fair use.

    However, even though the training is supposedly fair use, that doesn’t mean that the distribution of the output of such algorithms is fair use.

    The definition of “this software” is crafted to exploit this discrepancy.

  16. But maybe the output of the algorithm is under fair use as well.

    If it is, then copyright disappears entirely from software. The reason for this is that we already use algorithms to transform our software. We call those algorithms “compilers,” and their output “executables” or “libraries.” No one claims that a source code’s copyright does not apply to the binary forms output by a compiler.

  17. What if the output of a machine learning algorithm is transformative? Would that not be enough to defeat copyright?

    A compiler’s output is also transformative, especially if it does optimizations. This especially applies if the compiler is doing link-time optimization using inlining with code from different sources. In that situation, a compiler is combining multiple sources in non-obvious ways, just as machine learning models do.

    A compiler can even transform an O(n) algorithm into an O(1) algorithm!

    In other words, unless GitHub Copilot wants to throw out copyright on software completely, this license will apply to the output of its model.

  18. Why didn’t you just add a clause protecting the output of machine learning?

    I think the definition is wonderfully broad in a way that is best for end users, which is my central purpose: to serve end users who are hurt most by proprietary software.

    In addition, I don’t know what sorts of things will be done to software in the future, and I want to future-proof this license as much as possible.

  19. Your extra restrictions make your license incompatible with the GPL and AGPL.

    I don’t think so.

    First, they are not extra restrictions; they codify something that I believe already exists in the GPL and friends.

    Second, even if they are extra restrictions (which would make this license incompatible with the GPL), I think I am okay with that.

    In fact, if my licenses are not compatible with the GPL and friends, then I will keep the terms I have and accept the incompatibility. I can do this because these licenses will mostly be used for code in a new language, which means that I wouldn’t be able to use existing code easily anyway.

  20. Your extra restrictions make your license non-Open Source.

    Once again, I don’t think so, and for why, see above. The new parts are not new restrictions; they are clarified.

    But even if the license is non-Open Source, I’m not sure I care.

    The reason is this: I believe FOSS licenses have failed. We have so many companies that have used the freedoms we have tried to give users in order to extract value (data or something else) unethically from those very users. They do this by claiming the rights of distribution that the FOSS licenses give them and then using those rights to distribute Open Source software to users in such a way that they don’t realize that they are being taken advantage of.

    The more I’ve understood that, the more I have come to realize that the current iteration of FOSS licenses do not work.

  21. But what will work?

    Remember how I said that companies claim the rights of distribution we give them? As it turns out, end users, so-called because they are at the end of a chain of distribution, don’t usually use distribution rights.

    That means that the next generation of FOSS licenses can probably more heavily restrict how licensed software is distributed while allowing for no restrictions on the other two freedoms of the four freedoms.

    I’m not ready to go that far yet. If I was, I’d add a clause forbidding ads in the software. But that is probably the sort of direction we need to go.

  22. Your license is actually viral, since it makes the license apply to the full output of algorithms.

    I carefully defined “source code” to ensure that was not the case.

    You see, while the license does apply to the entire output, the requirement is still to provide only the source code of the original. There is no requirement to provide the source code of the entire combined software.

  23. Why did you say that “this software” only includes output of algorithms that is itself software?

    Technically, you can run software through things like hash functions, which are algorithms, and the output is entirely unusable as software. Saying that the license would apply to output like that would never work.

    The same goes for static analysis tools. They don’t usually output something that can be considered “software”; instead, they output a list of problems with the software. I wouldn’t want that to be affected by this license.

    In other words, that little part of the definition is required from making the definition so broad that it becomes useless.

  24. Your definition of “this software” has “this software” in the definition.

    That’s because the definition is recursive. The base case is the source code of the software, and then whenever the source code, or the result of transforming “this software” is transformed by an algorithm, the definition recursively applies.

  25. Why did you define “source code”?

    In order to make this license non-viral and because of the recursive definition of “this software”. See the previous question.

  26. Why did you write this FAQ when nobody has asked you any questions yet?

    To establish intent. If these licenses have to be tested in court, then if my intent is clear, that can help judges and juries resolve ambiguities and decide if a license violation happened.

    The GPL and AGPL did the same thing. However, in those cases, the licenses include the intent in the preambles to the licenses, which muddies the waters. The reason for this is because if the preamble conflicts with another part of the license, which part wins?

    To stop that from happening, I set forth my intent in this FAQ, but I also explicitly made it a separate document (in the repository). That way, if the FAQ conflicts with the license, the license wins hands down.