AnDOSBox seems to supply sources if you buy their app but that is not how the GPL works, if I understand it correctly.

That is how the GPL works, your understandings are incorrect.
READ before rant

rui.araujo wrote:

AnDOSBox seems to supply sources if you buy their app but that is not how the GPL works, if I understand it correctly.

Actually this is how GPL works...to my understanding. GPL specifies that you must provide the source (or a written offer) to anyone you distribute the binary to. It does not say you must provide the source to everyone in the world. A better question would be, how does one verify GPL is respected without buying the software?

Actually this is how GPL works...to my understanding.

From the licence 2b)

b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

When I read this I assume that this include the case when someone published a derivative application on Google Play.

By the way, I searched the forum for this kind of discussion and did not find one. I am not a lawyer so I am really trying to understand why this is okay.

It does. But this only means you can distribute the app yourself under the terms of the GPL license after you acquire it. Nowhere does it say, the original distributor must give you anything if you do not get the software in the first place.
The source code part is actually in Section 3 and it only mentions that you need to accompany the Program with the source code, again it does not require you to give it to everyone on demand.

Ok. Got it. A bit immoral on my opinion.

This also means that's nothing stopping someone from buying one of the paid ports and releasing a free or much cheaper version of their own. 😉

In my opinion, the moral way to do this would have been to publish the binary on the Store while providing the sources in their website to everyone as the original project.

The fact that the original authors can't get a copy of the derivative work without being charged for that seems a bit odd.

Thanks for the reply.

I'm sure the original author will get the source without paying 😉

rui.araujo wrote:

This also means that's nothing stopping someone from buying one of the paid ports and releasing a free or much cheaper version of their own. 😉

Of course, that's the beauty of GPL 😀. That's probably also the reason why many (most?) of the GPL software is free in the first place...

rui.araujo wrote:

In my opinion, the moral way to do this would have been to publish the binary on the Store while providing the sources in their website to everyone as the original project.

This might be moral, but the license does not require it. First of all, the license only covers the distribution part (an agreement between the distributor and the receiver), it cannot cover anybody else who is not involved in this process. The second point might be that wide distribution might be costly so again it is not required. I might add that the license even allows you to charge for the sources (which must be "no more than your cost of physically performing source distribution").

rui.araujo wrote:

The fact that the original authors can't get a copy of the derivative work without being charged for that seems a bit odd.

True. But the original authors might not even get a copy even if they want to pay. Think of Google and their linux use...they are not distributing it, they use it internally so they are not required to release the sources. And again, the original authors are not involved in the process of distribution. But they have the right to terminate the license to the distributor if they do not comply with the license. But how can they verify that without buying the software itself? 😀