My employer wants to publish a paper about software and make it open-source under the GPL, but they want to know who is interested and downloads it.

  1. Is it legal to ask people to fill in a regular registration form in order to download the code?

I am asking this because open-source GPL code should be accessible without restrictions, but at the same time I am not obliged to distribute all GPL code that I have.

  1. Is it possible that after registration users get a link to a GitHub repo that is otherwise hidden?
  • I assume "the code" you require registration to download is the whole software? Or is there a binary which doesn't require registration, and then registration is required just for the code?
    – Ángel
    Aug 29, 2020 at 2:19
  • My intention is to only the source-code, it is then possible to create a binary from it, if needed.
    – Andrey
    Aug 29, 2020 at 12:03
  • 4
    Note that if you distribute your code under the GPL, the first person to download it can create a github repo and distribute it for free and that will probably be more popular than the one that requires registration... Aug 30, 2020 at 8:42

2 Answers 2


Is this legal to ask people to fill in a regular registration form in order to download the code?

Absolutely. You can even require people to pay money to download GPL'ed software. What you can't do is to stop them redistributing it afterwards (provided they do so under the GPL). So while you may be able to record the people who downloaded it from you, you won't know about people who got it from one of those people.

Is that possible that after registration users get a link to a github repo otherwise hidden?

That would seem to me to be a fairly normal mechanism for distributing software only after some condition (registration, payment, etc.) has been satisfied.

Edit: several comments are very properly making points about source-access obligations. I'd ignored the issue in my answer, because in the case of a scientific paper, there may not be a "binary form", as opposed to a "source form" - which is also why a copyleft CC licence might be more appropriate than the GPL. But the points being made are all very valid, and I am grateful for them.

  • 2
    Yet I understand that obtaining the code must not be more onerous than obtaining the binary; you may not give away the binary for free and ask money for the code. Every user of the software has the right to obtain it without further hassle (they might need to prove that they bought / obtained it from you, if available in several places). Aug 28, 2020 at 23:23
  • 1
    @planetmaker That sounds right, as long as the binary is GPL licensed. If, like in this case, you own the copyright, you can also distribute it under an alternate license and "hide" the code behind a paywall or other distribution mechanism. Aug 29, 2020 at 2:19
  • @planetmaker - The exception is if you own the copyright. In which case you are free to use any licensing you want. There are libraries I've used before that are licensed under a proprietary license as a DLL but you can purchase the code as either GPL or MIT license depending on weather you need to incorporate it in a GPL compatible project. To the author of the code, his own "license" to the code is he is the owner of copyright thus he himself is not under GPL
    – slebetman
    Aug 29, 2020 at 8:11
  • "there isn't really a "binary form", as opposed to a "source form"" Isn't a PDF a binary output of something like a LaTeX input? Aug 31, 2020 at 9:29
  • If the paper was distributed in PDF form but prepared in some other, more easily-editable form, I agree, the "traditional form for making changes" corresponds well to the "source form".
    – MadHatter
    Aug 31, 2020 at 9:53

Disclaimer: I am not a lawyer, this is my understanding as a long time member of the open-source community.

First things first, if your employer owns the copyright to all the code they are not bound by the GPL, the GPL only binds them if they are redistributing GPL code owned by others.

Secondly, (unless you have previously made a physical distribution under option 6b) there is nothing in the GPL that requires offering the code to everyone, so even if the code is a derivative work of other GPL code, putting it behind a registration form should not be a problem from that angle.

The one area where you may have to be careful is if the work is a derivative of other GPL code and you are distributing the work in binary form. In this case you must comply with one of the options listed in section 6 of the GPL.

Options a, b are only relavent to physical media distribution. Option c is only relavent if the distribution is noncommercial and the place you got the code from used option b. Option e is only relavent for distribution through peer to peer networks (and mostly references option d anyway).

So that leaves you with option d.

d) Convey the object code by offering access from a designated place (gratis or for a charge), and offer equivalent access to the Corresponding Source in the same way through the same place at no further charge. You need not require recipients to copy the Corresponding Source along with the object code. If the place to copy the object code is a network server, the Corresponding Source may be on a different server (operated by you or a third party) that supports equivalent copying facilities, provided you maintain clear directions next to the object code saying where to find the Corresponding Source. Regardless of what server hosts the Corresponding Source, you remain obligated to ensure that it is available > for as long as needed to satisfy these requirements.

I would interpret this as it being ok to put the source and binaries behind the same registration wall. But not to distribute the binaires openly while putting the source behind a registration wall.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.