I want to develop a specific module from a GPL 3 software in a partnership with a third company to share the costs.

Can we each use it for our companies (meaning internal use) without having to publish the code? Or would this partnership be considered as "external use"?

If we use it as "internal use" without publishing the code, why would it be considered as a violation?

  • 1
    Welcome to OS.SE! Have you read this question, which deals with sharing source for development between two different companies which are both subsidiaries of the same parent? Because it's pretty clear that the transfer from company A to company B counts as conveying, in the GPLv3 sense, and therefore GPL obligations apply to the transfer. This will be no less true when A and B are completely independent companies.
    – MadHatter
    Sep 20, 2021 at 8:27
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    @MadHatter: Nevertheless, there is nothing in any version of the GPL which requires you to publish the code. You merely have to share it with your counterparts in the other company (under the terms of the GPL, so they could share it further, if they wanted to).
    – Kevin
    Sep 20, 2021 at 9:00
  • @Kevin Thank you for your feedback. Is this clarification available in the GPL 3 regulation? I just can't find this distinction in the literature. Thank you!
    – MelOn
    Sep 20, 2021 at 9:02
  • @Kevin I agree, and I'm not saying otherwise; I'm merely trying to establish how much research the OP has done, so I can avoid duplicating anything that's already available on this site.
    – MadHatter
    Sep 20, 2021 at 9:20
  • I think this is answered in the GPL FAQ. See gnu.org/licenses/gpl-faq.html#GPLRequireSourcePostedPublic
    – Brandin
    Sep 20, 2021 at 12:47

1 Answer 1


Firstly, GPLv3 doesn't mention "internal use" at all, so the answer to the question in the title is "nothing".

That said, we already have a question that discusses whether sending code from one company, A, to another company, B, constitutes distributing it, and thus triggers GPL obligations. It concludes that it does, because A and B are separate organisations, even in the context of the question where A and B are wholly-owned by the same parent company, and so the analysis holds in your case, when A and B are unrelated.

The linked question also examines what the GPL FAQ has to say about how internal use within a single company doesn't constitute distribution, but notes that it's clear that "when the organization transfers copies to other organizations or individuals, that is distribution", which agrees with our analysis.

So: when company A gives a copy to company B, this is distribution, and the copy must come with full source code and GPL rights. However, the GPL FAQ also notes that you are not obliged by the GPL to share your code; it simply requires that when you do share your code, it must be done so under the terms of the GPL, and so with full source.

It therefore seems to me that, as long as both companies have full source code under GPL, each can share copies with its own employees under the traditional restrictions of employment, and have them develop and improve it, for internal use by both companies A and B. However, should either company choose to give a copy of this code to some third-party, this conveyance will need to be done under GPLv3, with full source and all GPL rights provided. Third-party, in this case, includes not only potential customers, but also contract resources retained by either A or B.

  • Thank you very much for this analysis. Let me ask you one last underlying question. If I can only disclose the source code to the other company, without releasing it to the public, can I contractually prevent that company from releasing it as well? Thx !!
    – MelOn
    Sep 20, 2021 at 15:01
  • In my opinion, only if A is the sole rightsholder, and therefore free to distribute under other terms. The FAQ addresses this also, and says that NDAs are impermissible. As long as A and B mutually-agree to keep this code between them, that's OK, but either may at any time exercise their GPL rights, and redistribute more widely under the usual terms.
    – MadHatter
    Sep 20, 2021 at 15:10
  • Thank you very much for these answers, I appreciate it.
    – MelOn
    Sep 20, 2021 at 15:13
  • @MelOn you're very welcome. Please note that local etiquette is that once you're happy with an answer to your question, you accept it by clicking the "tick" outline next to it, which drives the reputation system for both you and the author of the accepted answer. My apologies if you already know this!
    – MadHatter
    Sep 20, 2021 at 15:16

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