Under my interepretation of the GPLv3, specifically the following:

“Object code” means any non-source form of a work.


You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source...

Now, let's assume that, by some means, I convert some GPLv3-covered source code into a physical object (e.g. a poster). Obviously, if I sell or give the poster to someone else, I must provide them with the Corresponding Source under section 6.

The part my intuition isn't giving me a clear answer on is this: if I instead make this object available for viewing (e.g. I hang the poster on my wall), but it does not leave my possession, am I still obligated to make the Corresponding Source available to anyone who views it?

2 Answers 2


The GPLv3 says

To “convey” a work means any kind of propagation that enables other parties to make or receive copies.

However, public display does not make a copy of the work, and I strongly expect that viewing a public display does not cause the viewer to "receive" the work, either (at least in the United States).

Furthermore, consider that "conveyance" is a kind of "propagation", which is defined as virtually anything that requires copyright permission:

To “propagate” a work means to do anything with it that, without permission, would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private copy.

This is relevant in the United States since 17 USC §109(c) says of public display:

(c) ... the owner of a particular copy lawfully made under this title ... is entitled, without the authority of the copyright owner, to display that copy publicly, either directly or by the projection of no more than one image at a time, to viewers present at the place where the copy is located.)

Therefore if you are displaying a poster lawfully created under the GPL to physically-present people, that display does not require any permission from the copyright holder, so the act is neither propagation nor conveyance.

Also consider this GPL FAQ item:

If someone installs GPLed software on a laptop, and then lends that laptop to a friend without providing source code for the software, have they violated the GPL?

No. In the jurisdictions where we have investigated this issue, this sort of loan would not count as conveying. The laptop's owner would not have any obligations under the GPL.

If physically lending the work does not constitute coneyance, neither should we expect that making the work available for viewing (without any change of physical possession) constitutes conveyance either.

  • 1
    What if you display it in a physical place and they take a photo? Jun 11, 2018 at 0:12
  • The GPL doesn't require you to give a copy of GPL software to other people. Normally, if someone comes into contact with GPL code, and helps themselves to a copy, they don't magically acquire GPL rights. It seems to me that someone taking a photo of a licensed work has the same problem; they may have committed a copyright violation, but they haven't magically become a legitimate licensee.
    – MadHatter
    Jun 11, 2018 at 6:06
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    I think curiousdannii makes a good question: If I put a poster showing the source-code on public display then others can take a photo of that and feed it into optical character recognition software, and thus have the source in machine readable form.
    – Panu Logic
    Jun 11, 2018 at 15:21
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    @PanuLogic indeed, but the crucial difference is that they took it; they were not given it.
    – MadHatter
    Jun 12, 2018 at 14:11
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    @MadHatter Yes But, if "To 'convey' a work means any kind of propagation that enables other parties to make or receive copies" then doesn't public display (of a large poster containing the source-code etc.) indeed enable other parties to make copies of it? (because that enables them to make a photo of it then feed that into OCR)
    – Panu Logic
    Jun 13, 2018 at 3:11

No. Your example of viewing a poster is comparable to allowing someone access to a (server-generated) web application. In that case, the code on the server is also not distributed and you are not required to provide the sources to your website's visitors.

  • Assuming the source code is visible on the poster, I don't think this answer is correct. Anyone who sees the poster could read and potentially copy the code from it... it's more like a web page that is displayed on screen than like code that runs on the server without being distributed.
    – jkdev
    Jun 17, 2018 at 10:23

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