We are building a display-less system, which interacts with the user only through an audio interface (and some buttons).

Our system is based on Linux, and as such we are using several GPL/LGPL components. Now, the licenses explicitly say that a copy of the license should be provided with the program (which we are effectively distributing with the device we are building), but in our case the license text cannot be shown to the user. Morevoer, we did think of printing the license texts, but in that case this would hinder us when delivering updates to the product.

Our current idea is to reproduce, using a TTS, the license text to the user, do you know if there's some other way to achieve compliance with the license terms? What if we didn't have an audio interface either?

  • How are you providing the updates such that you can't provide a leaflet or pdf with the new license texts along with it? Jul 30, 2017 at 10:29
  • Updates are provided over the air, without physical access to the device. I could upload a pdf to the device but I wouldn't be able to show it since we don't have any display. As for pre-generating audio: my first concern was about the size of the resulting audio files, but after OGG compression and "clustering" of the licenses (i.e. sharing the same audio file among different packages with the same license), I got it down to an acceptable size. This could be a solution for us, I was wondering if there were other ways that I was currently ignoring
    – Croj
    Jul 30, 2017 at 14:58
  • @Croj: You seem to only ask about the license text, but what about the source code itself? However you provide the source code, you can provide the license text that way, too, no? -- Or is your question about the source code as well as the license text?
    – unor
    Jul 30, 2017 at 18:11
  • You're right, but actually, after re-reading the GPL it seems that if I distribute only the object code, then I have to give access to the source code (durable physical medium or written offer), and if I distribute the source code then I must accompany it with the license text as well, am I right? In this case, there is no need to have license text + source on the device itself, assuming everything is in place to provide them to any party interested. Is my understanding correct?
    – Croj
    Jul 31, 2017 at 7:34

1 Answer 1


You not only have to provide the license, but also the source code itself (in the preferred form for making modifications to it). Even if it would be allowed to provide the license as audio (not sure if it is), this wouldn’t be the case for the source code (as it’s not the "preferred form for making modifications"). You should bundle the source and the license.

Section 6 of the GPLv3 describes how you can provide the source.

When selling a device (on which the software runs), you can either

  • enclose a physical medium that contains the source (6.a), or
  • enclose a written offer saying that you can give out such a physical medium or that the source can be downloaded from a server (6.b).

For the software updates, 6.d applies (unless they come on a physical medium, in which case also 6.a/6.b apply).

Typically the easiest way would be to offer everything for download on your server. When selling a device, enclose a paper with the URL (+ username/password, if you prefer) for the page where you upload the software and its source of the version initially installed as well as of all updates.

In addition, you could of course also provide a TTS menu point in your software, which explains which licenses apply, where the licenses can be read, and where the source can be downloaded.


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