Talking with lawyers is not pleasant anytime! 😉

According to the GPL v2, it is quite clear: (TL;DR yes, you need to provide also to third parties if requested)

3. You may copy and distribute the Program [..] in object code or executable [..] provided that you also do one of the following:

a) Accompany it with the complete corresponding machine-readable source code [..]

b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,

So you either provide the source code alongside with the binary to your customer, or allow any third party to request a copy of it. But being precise, it do not force you to contribute back or make any change public. Not that it makes GPL any more business friendly thought.. 😉

Thanks Sergio.

From my own experience dealing with these licenses and talking to lawyers the main problem is that opinions vary as to what they mean – what linking pertains, what you need to offer and to whom. This makes these licenses problematic.

As a quick question – does the fact that I am providing a GPL module in binary form to individual X means that if individual Y asks me for the source code is entitled to receive it? The answer is most probably yes, which ends up diluting a lot of the technological advantage vendors believe they have.

The main differences between them is that LGPL allows you to link against non-GPL code, GPL forces any linked code to be GPL, and AGPL forces any “used” code (linked, via network apis, etc) to be GPL.

Been GPL *just* means tha you have to make available the the source code to anyone that you provide the binary to whenever they request it. You don’t have to make it public, or contribute back to the project any change you make at all. As you say, AGPL would force you to make the source code avaiable to anyone using your service.

Thanks Lennie.

The selection of a license as someone who is writing the module is indeed important. I tried taking the view here of the person who needs to decide if he wants to adopt a module and how the license of that module affects the decision.

It is because they are trying to establish a standard, you want the reference implementation to be available for as many people as possible to include in their commercial closed-source applications.

For example, the creators of the GPL license, the FSF, also advised the developers from Xiph.org to use the BSD license for their OGG-codec-libraries many years ago to make sure the OGG-codec can be used by as many as possible. For example at that time many game developers used ogg for their sound files.

Tip: I think the Github also has a useful site:
http://choosealicense.com/
http://choosealicense.com/licenses/

Looking back at this article the GPL forces more freedom for the software it is covered under because it does not allow more strict rules to applied. But the Apple store does have extra restrictions:
http://www.zdnet.com/article/no-gpl-apps-for-apples-app-store/

I believe it eventually got solved in some way because I think VLC is in the appstore at this time. But I have no interest to look it up right now to find out how this is now done.

iOS is limiting when it comes to GPL I am told. Something to do with the App Store rules developers need to abide with. Not sure if that’s true or an urban legend.

In general, it is easier to deal with non-permissive licenses on the server side – especially if what you sell in the end is a service and not something that gets installed somewhere else.