4

From my vague understanding of this subject I assumed that if I make an installer for my program and it contains a GPL library my code would have to fall under GPL. However, I noticed yesterday when installing Ubuntu that its installation had checkboxes (selected by default) to install non free software.

This question specifies about programming behavior and says that my program wouldn't fall under GPL as long as the library can be seem as separated programs but it does not say anything about making a common installer for the package.

I saw this answer saying about common installers in StackOverflow in Portuguese and it does say about a common installer making the code fall under GPL.

If I create an installer for the library and put my non-free program that uses that library there as an option my program wouldn't fall under GPL ?

  • 1
    -1 for not reading the other question properly. There is nothing written about common installers", the term "install" does nowhere appear. And the topmost answer says it all - it depends on how your program uses the GPL lib. When your program uses the GPL lib by linking it directly, you must use GPL for your program. Just using a common installer for a GPL and a non -GPL program (for example, where the non-GPL prog does not use the GPL lib) does not enforce GPL on the combined package. – Doc Brown Aug 11 '14 at 19:25
  • 1
    ... and in Ubuntu the installer should only provide non-free software which uses GPL software only the way described in the other topmost answer as well (using the command line interface, but not by using a shared adress space) – Doc Brown Aug 11 '14 at 19:29
  • @DocBrown, now I have an answer and I edited the question trying to make it fit better the How to Ask. – Mansueli Aug 11 '14 at 19:38
  • 2
    Ok, changed from -1 to +1, this question is much better now. Though you probably missed this GNU GPL FAQ entry, which is pretty clear: gnu.org/licenses/gpl-faq.html#GPLCompatInstaller – Doc Brown Aug 11 '14 at 19:41
7

The part of the GPL FAQ which says

We believe that a proper criterion [for drawing a line between two separate programs] depends both on the mechanism of communication [...] and the semantics of the communication.

is IMHO really clear - putting separate GPL and non-GPL programs in one installation package has nothing to do with communication between those programs. So this fact alone is no criteria for enforcing GPL on a non-GPL software.

Furthermore, the GNU GPL FAQ says:

The installer and the files it installs are separate works. As a result, the terms of the GPL do not apply to the installation software.

This means not even the installer has to be GPL when used for packaging GPL modules (and why should other non-GPL modules in the same package become "GPL" when not even the installer has to?).

However, you are talking about

a non-free program that uses that [GPL] library

and not about

a non-free program that uses a [GPL] software through pipes, sockets or a command-line interface

So, when your program uses a GPL library (by linking against it), the GPL will apply and you have to put your own program under GPL due to the fact you are using a standard linking mechanism, but not to the fact you put those modules into the same installation package.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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