Would the usage of proper make joxa under GPL?

[chrisliu529]

As proper is under GPL: https://github.com/manopapad/proper/blob/master/COPYING
Would the usage of propler, though only invoked in 2 or 3 test files, make the whole joxa code under GPL?

[KlausTrainer]

Short answer: yes.

Generally, as soon as some piece of software extends GPL software, or as soon as it is combined with GPL software such as to form a larger program, the GPL applies to that very piece of software and the resulting combination as well. However, that doesn't prevent people from using different licenses for their software that is based on GPL software, as long as the particular license is compatible with the GPL [1].

As PropEr is distributed under the GPL, version 3 or later", and Joxa is distributed under the Apache License Version 2.0, we have a compatible combination of software licenses [2].

[1] http://www.gnu.org/licenses/gpl-faq.html#LinkingWithGPL
[2] http://www.gnu.org/licenses/license-list.html#apache2

[ericbmerritt]

@KlausTrainer is absolutely right. However, it is a point of ambiguity that I would like to resolve. When Proper was originally integrated into Joxa I had the impression that the Proper license would be changing to something more acceptable for a mixed project. That never happened. At some point we will pull proper out. It may be possible to replace it with triq if not we can get similar test coverage from more traditional approaches.

[KlausTrainer]

@ericbmerritt I can't see any "point of ambiguity" here. To me, this issue looks quite clear, and I don't think that we have to do anything about it. Could you please explain what problem you see if Joxa is being, let's say, "infected" by a GPL version 3 library? I can't think of a situation where this would become a problem for anybody, as it doesn't change the fact that Joxa is distributed under the (perfectly compatible) Apache License Version 2.0.

[ericbmerritt]

@KlausTrainer Any time property based testing is involved we include headers and the like from the source of the test libs. In this case that is from proper. We then redistribute that code. That brings us under the requirements of the GPL. That is, as it currently stands Joxa should actually be GPL.

The APL and the GPL are compatible in the fact that they are not mutually exclusive. They are not compatible in the idea that you can use a GPL library in code that is licensed as APL and have that code remain APL.

[KlausTrainer]

Well, of course. Thanks for the explanation! So for instance, we would have to make sure to not include any PropEr tests in our distribution, if we chose to distribute without source code only. I understand how this can be an issue, as there's yet another thing to keep in mind and take care of.

[ericbmerritt]

I am mostly tempted just to remove the proper tests completely for now. I suspect that is going to be the long term viable thing here.

[fommil]

This just means that your tests are GPL. They are, arguably, a standalone application. It does, however, mean that any distribution including your tests needs to be GPL.

[fommil]

Intro to licencing here: http://fommil.github.io/scalasphere16/ although not really enough for you to learn much more on this exact topic. I e you're going to just remove the GPL dependency in your tests, that's probably the easiest thing to do.

[ericbmerritt]

In this case the tests are all distributed with the code, there is nothing in the system to strip them out. :/