I just got an email from a developer who works on the nifty cairo-dock application, pointing me to a thread about licensing issues.
A bunch of months ago, he’d emailed me asking about how to best use code from my Xfce Mailwatch Plugin in cairo-dock to add mail-checking capabilities. At the time, I was pretty stoked that someone else had actually found my code useful enough to incorporate into their program, and offered my encouragement.
Sadly, though, licensing ugliness has reared its… well… ugly… head.
When licensing code under the terms of the GNU GPL or LGPL, the FSF suggests (and most people follow) that you license under “or (at your option) any later version” terms, which means that, while you initially license the code under the version of the GPL or LGPL of your choice, someone can later take your code and relicense it under the terms of a later version of the same license. This also makes the code automatically compatible with future versions of the license.
You might think this sounds pretty good for convenience and licensing compatibility, and you’d probably be right.
However, this isn’t so great from a philosophical perspective, at least from my philosophical perspective. The problem I have is this:
Licensing a work under “GPL version 2 or later” terms means that I am implicitly agreeing with any new restrictions that the FSF dreams up (or any existing restrictions the FSF wants to drop), forever. I’d basically be saying that I agree with something that doesn’t exist yet, and could take any shape or form imaginable.
Don’t get me wrong: in general, I think the FSF is good people, and I agree with their message for the most part.
But I don’t know them, personally, and I don’t agree with them 100%. And I don’t know who’s going to be running the FSF next year, or in five years, or in 20 years. So how can I know, or even have reasonable belief, that their philosophies and values will align with mine such that I’ll agree with future versions of their licenses? There are already parts of version 3 of the GPL and LGPL that I don’t completely understand or agree with, so why should I expect that versions 4, 5, or 10 will be completely to my liking?
The short answer is: I can’t.
And so, for the most part, I release my software under “GPL version 2 only” terms. (Because I’m a bit lazy and don’t want to make a big stink, I’ll release code under “or any later version” terms if I’m contributing to an existing code base that uses those terms.)
it really pained me to have to answer that email saying that my code’s licensing (GPLv2-only) wasn’t compatible with theirs (GPLv3-or-later), but it’s the truth, and there’s not much I can (or want to) do about it.
The only solution I can think of (I’m not a lawyer, of course) that allows them to use my code is that they relicense their code under GPLv2-or-later terms. Of course, then they lose any restrictions that the GPLv3 has over the GPLv2, which I assume they’d prefer to have, since that’s how they’ve licensed their code.
(Before anyone says it, another possible solution would be for me to relicense under LGPLv2.1. The problem with that is one I’ve discussed before: section 3 of the LGPLv2.1 explicitly allows a recipient of the code to relicense the code under regular GPLv#-or-later terms, regardless of the only/or-later status of the original LGPL licensing. This of course completely defeats the intent of my rationale above.)
And so, the OSS licensing mess has caused yet more pain to people who just want to share code and avoid duplicating effort. I love the GPL. I really do. But I also hate it.