I hate it when people repeat gossip without actually knowing what they're talking about, but here I go doing that very thing!
My ignorant understanding of this issue is that it has not been tested in court, and there are differing opinions about whether or not the strategy you describe is open to legal action.
In the GPL v2.0, there's some language in section 2 that suggests that if you ship your closed-source app with the open-source app, then you're licensing both under the GPL. GPL2 isn't super clear on the issue.
In GPL 3.0, there's a lot of language in section 1 about "Corresponding Source" which I believe was believed by the authors to specifically close the loophole you describe.
So, if I were trying to obey the letter of the law religiously, I wouldn't do what you describe. And if I was trying to obey the _spirit_ of the law, I'd do what a previous employer of mine did: personally contact the authors of the GPL code in question and verbally ask for permission.
> In the GPL v2.0, there's some language in section 2 that suggests that if you ship your closed-source app with the open-source app, then you're licensing both under the GPL. GPL2 isn't super clear on the issue.
That's unequivocally false.
It's not even a matter of GPLv2 making vague suggestions or being unclear. It's explicit and says the exact opposite of what you've written.
You can ship closed source apps and free software together. If that wasn't the case, then none of the Linux-based consumer devices that ship with proprietary userland would be able to exist.
You certainly can ship non-free software and free software together, in the general case. I was, of course, talking about the context of the parent comment, which was about (non-free) software that, as a fundamental part of its operation, use free software via a well-defined non-link-time interface. Such as, for example, a GUI text-search tool that, to do its fundamental work, shells out to gnu grep.
My understanding is that the relevant part of the GPLv2 is (with emphasis mine):
"If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it."
I honestly agree it's pretty explicit, but disagree with you about what it says.
IANAL, but I have heard the analysis I gave from two independent sources, one of whom is a lawyer specializing in IP law, and the other of whom used to work with the FSF on policy issues.
As I say, my understanding (given to me by the aforementioned lawyer) is that this has not been tested in court.
My ignorant understanding of this issue is that it has not been tested in court, and there are differing opinions about whether or not the strategy you describe is open to legal action.
In the GPL v2.0, there's some language in section 2 that suggests that if you ship your closed-source app with the open-source app, then you're licensing both under the GPL. GPL2 isn't super clear on the issue.
In GPL 3.0, there's a lot of language in section 1 about "Corresponding Source" which I believe was believed by the authors to specifically close the loophole you describe.
So, if I were trying to obey the letter of the law religiously, I wouldn't do what you describe. And if I was trying to obey the _spirit_ of the law, I'd do what a previous employer of mine did: personally contact the authors of the GPL code in question and verbally ask for permission.