As far as I understand, it is well accepted that, for programs that are licensed under the GPL, the output of a program does not necessarily have to follow the GPL. This is confirmed by the "Basic Permissions" section of the GPL version 3:

The output from running a covered work is covered by this License only if the output, given its content, constitutes a covered work.

However, is it the case that the only reason the GPL doesn't necessarily need to be followed for an output is because the GPL says so?

What I mean is: after reading the Mozilla Public License v2 today, it seems it doesn't say anything about outputs generated by the program. So let's say I have a compiler licensed under the MPL v2, and I use this compiler to generate some executable called A. Does A need to follow MPL v2 terms, since MPL v2 doesn't say it does not apply to outputs?

I'm using MPL v2 as an example, but this question could be applied to any software license. Am I always allowed to assume my output can follow a different license, or does it completely depend on the license of whatever generated it?

  • To be honest, I don't think it answers it completely. If the most voted answer is correct, does the GPL only include that text I quoted as a safeguard measure? I don't think it has any effect if the output is "automatically" not affected by GPL
    – Solens
    Commented Jul 26, 2022 at 21:34
  • That is correct; even if the GPL said the output were covered, it would have no effect because copyright law doesn't work like that. Commented Jul 26, 2022 at 22:25
  • 1
    Possibly a duplicate of Generated content protected as well? which is largely a reproduction of the GPL FAQ item gnu.org/licenses/gpl-faq.en.html#GPLOutput
    – apsillers
    Commented Jul 26, 2022 at 22:42
  • 3
    The GPL also says other unnecessary things. For example, the GPL says "This License explicitly affirms your unlimited permission to run the unmodified Program." Legally speaking, a statement like this does not really need to be said, since copyright does not cover the act of running a program; copyright only covers making and distributing copies. I don't think it hurts for GPL to say that, though. And the fact that other licenses do not generally mention running a program, does not mean you need special permission to run a program which you have obtained legally, for example.
    – Brandin
    Commented Jul 27, 2022 at 4:44
  • See also the Law SE perspective on almost the same question here: Is the output of a generator tool copyrighted?
    – Brandin
    Commented Jul 27, 2022 at 11:49


Browse other questions tagged or ask your own question.