I have a question regarding the enforcing of the GPL license.

Let us suppose I am creating an IoT device using custom software linking/modifying GPL software. We assume that the software running in the IoT device is not accessible via conventional ways.

Case 1:

The client loans the IoT device. In that case, should I disclose the source code I developed?

The example I found closest to this case is the Laptop Lending section in the GPL FAQ. In that case, the device is still mine, and thus my own software runs and my own device and I do not need to release my source code. Is my understanding correct?

Case 2:

We sell the device to the client. In that case, I think we should disclose the source code the same way as television manufacturers using Linux as an OS disclose their sources.

  • If the software is under GPL version 3 and you can modify the software in the device, you need to provide information to allow the user to modify the software as well.
    – EMBLEM
    Jul 19, 2016 at 14:55
  • See my answer: lending a laptop to a friend is not the same as a company loaning an IoT. There are precedents in France with a lawsuit against Free.fr and their Freebox for violating the GPL. Jul 23, 2016 at 9:43
  • Note that if the software is not accessible and you use GPLv3 software, you may be violating GPLv3.
    – user253751
    Apr 26, 2020 at 20:14

2 Answers 2


I think that in both case the GPL would apply without any ambiguity.

A commercial loan is different than lending a laptop to a friend. I would consider this as conveying hence redistribution, etc. An IoT is nothing special in this regards: the FSF GPL FAQ you reference talks about personal loans, not commercial ones.

And in all cases disclosure and attribution would be needed too even if this becomes challenging on tiny devices.

The GPL talks about redistribution and conveying. Whether this was through selling or lending does not matter in most cases IMHO.

And there is a precedent in this domain: the French ISP free.fr used to argue about ~ 10 years ago that the set tops and DSL freebox CPEs they provided to their customers were lent and not sold hence the GPL copyleft terms did not apply. In 2008, There was a lawsuit. Free.fr could not hold their positions and they settled in 2011.

They now redistribute the copyleft source code included in their devices, albeit in a fairly subdued and the most minimalist way they could. It does not look like they do this in a happy way :D

Note also that I once met a similar case where a commercial company was lending devices for trial. The lawyer involved at the time was quite clear that in this case the GPL did apply all right.

Note: Several articles I linked to are in French.... Use a translation web service!

  • I am French, so no need for translation :) Thank you very much for your detailed answer.
    – Olivier
    Jul 24, 2016 at 10:18

I think both answers are correct. As long as you own the device (case 1) you don't have to pass on the source code and the rights guaranteed by the GPL.

If you sell the device you have to add a copy of the license and the source code. Instead of the source code you could also add a offer to provide the software on request. But typically this means more work for you so I would distribute the source together with the device.

Keep in mind, that you don't only have to distribute the source code of the GPL program you use. But also license all modifications on the program as GPL and everything which is a derivative work of the GPL program. For example a program you wrote which depends on (links to) the GPL program.

  • Loaning a laptop to a friend is different from a loan by commercial entity. You are reading between the lines of the GPL FAQ wrong IMHO. See my answer for details why. Jul 23, 2016 at 9:40

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