If a project has no a license or has unknown authors, is it public domain?


3 Answers 3


As usual, IANAL, consult a lawyer for legal advice. That said:

No. The default is "all rights reserved". You are not allowed to copy someone else's work without the author's explicit permission, even if the author is unknown.

Works are free for you to use under the following circumstances:

  • You have written it yourself, and haven't transferred your rights to anyone else (note that in some jurisdictions, all your intellectual property is automatically transferred to your employer, even if the contract doesn't state this explicitly).
  • The author has explicitly released the work into the public domain. Note that some jurisdictions in the world do not acknowledge this; in those countries, you may still be violating the law (although it is unlikely that the author is going to sue).
  • The copyright holder is a government institution or similar legal person whose works are in the public domain by law.
  • The author has given you explicit permission.
  • The author has released the work under a permissive license (e.g. MIT, Apache, or BSD licenses). You are still bound by that license though.
  • All the authors have been dead for long enough (where "long enough" means 70 years in many countries, but the figure may differ either way). I doubt you'll see this in the software realm anytime soon, but it's very relevant in arts and music.

I am not a lawyer, but my understanding is that no, it would not be in the public domain. See the first paragraph on this wikipedia page about the Berne Convention. Basically you have to explicitly give up the rights, otherwise you have them, so unless you can find where it is put into the public domain it is not there. I am sure it is far more complicated than that, but I think I would start with that.

Here is a stackoverflow post with some more perspective.

  • +1. Intellectual copyright is implied when not explicitly stated.
    – Craige
    Jun 5, 2012 at 15:16
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    So don't use non-licensed code, it could suddenly get a (pay me) license attached.
    – Paul
    Jun 5, 2012 at 15:45
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    I never said anything about not being able to use it, I said it was likely not in the public domain. As mentioned above, I am not a lawyer and you would likely want to talk to one before getting too involved with code that has an unknown license. You can use anything you want, but you are opening yourself up to them showing up with a license that could cause you some hassle (as @Paul mentions). In general I think you want to know what the rules are for using code before using it.
    – asjohnson
    Jun 5, 2012 at 16:25
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    @user14284 - I would stay away from it completely if you don't know the license or the owner. There are too many things that could go wrong. Before you know it, you're using parts of this code in your mission critical application, and the owner shows up one day intent on collecting his licencing fees. Just because you don't know who the owner is, doesn't mean the owner won't recognize their work when they see it.
    – Craige
    Jun 5, 2012 at 16:43
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    It's like your mother told you: Don't touch that code... you don't know where it's been.
    – Caleb
    Jun 5, 2012 at 18:53

As mentioned consult with a lawyer but in the US and most western countries no. Copyright exists on something regardless of if you explicitly claim it with a (@C) symbol. Generally if you are paid to create the code your employer owns it unless you specified otherwise in your employment contract. If it is made by yourself you are the copyright holder.