I've forked the protpy package into propy3 in order to make it usable for Python 3 users. I'm not a user of that package myself and have no clue of protein computations. However, in order to make it useful and ensure it works, I ended up spending way more time on it than I originally thought.

Now people want me to add a license file. Several attempts to reach the original authors were unsuccessful, so I cannot simply align with them what they want.

The original website mentions GNU GPL v2, so I will put the forked project under GNU GPL v2 as well.

I feel like the original authors are still the authors of this package, as most of my changes are not affecting what the package does, but how it's structured / how it works / adding tests / dealing with community support. However, I do want to change some interfaces.

Now I wonder: Is it even ok to leave them in the "author" field? Should I add myself to them? Should I remove them from the author field and mention in the README that this was forked from them?

1 Answer 1


You have forked a GPLv2 package, and created a derivative work therefrom. You are curious about the licensing and copyright arrangements for the new work. Fortunately, neither of these are in any doubt; the original authors have made their requirements clear simply by releasing their work under the GPL.

GPLv2 s2b requires that the modified work be released under GPLv2, which apparently is what you intended to do anyway, so that's good.

Both you and the original rightsholders have a copyright interest in this modified work. You should add your copyright notice to any files you have edited, alongside the existing copyright notices. Any files you have created de novo should bear your copyright notice at the top. If in addition you want to collect this all into a LICENSE file that's up to you, but it's not required. You do need to include a copy of the GPL, if it's not already there.

  • 5
    From eyeballing the repository, the original authors haven't included any copyright notices, or in fact a copy of the GPL at all. Which makes it all a bit of a mess :( Commented Feb 18, 2022 at 23:07
  • @PhilipKendall you're not wrong, but if they are the original authors, as the text snippets that look a bit like copyright statements suggest (they give both names and dates), they're not obliged to. The OP could simply leave those as they are, adding his/her own copyright statement below; and including a copy of the GPL is hardly onerous or difficult.
    – MadHatter
    Commented Feb 19, 2022 at 7:52
  • Thank you for your help! I've now added the license notice to each file (see PR). I've removed the two original protpy authors from the new propy3 package I've created as I'm uncertain if they want to be connected to that project. As now every single file contains the license notice and their names, I hope/guess that this is fine. Commented Feb 19, 2022 at 9:33
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    @MartinThoma you're welcome, though I agree with your observation that Google's license summary for the original version is GPLv2, not GPLv2+, and the code itself doesn't give us much reason even to think that ("For academic users, it is free of charge. They can freely use and distribute it. For commercial purpose, they must contact the author"). Google are conveying it to you, so I think you might reasonably take them at their word about that being under GPLv2, but I don't see any reason to think you can unilaterally shift that to GPLv2+.
    – MadHatter
    Commented Feb 19, 2022 at 11:29
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    @MartinThoma: FWIW, if the original authors hadn't specified a version of the GPL at all (as they apparently hadn't in the setup.cfg file), you'd be (per GPLv1 §7 and similar terms in other GPL versions) free to choose any version(s) of the GPL. But since they did specify GPLv2 in at least one place (the "Project Information" metadata), that probably means you have to stick with that. At least that's the safest choice, unless of course you can find some place where they used (e.g.) GPLv2+, or contact them and ask. Commented Feb 19, 2022 at 14:52

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