Someone could "use your code and not give back" while staying perfectly within the limits of the GPL, though. For example, they could use and modify your software in an internal package.
This is something that's always been slightly unclear to me. I think you should be able to do whatever with any copyrighted code that's been published (by someone who has the right to do so) for your own personal use, regardless of license. Clearly publishing this copyrighted is not possible without some kind of license.
However where 'personal use' ends and 'publishing copyrighted code' begins is not entirely clear to me. Does an internal tool in a company still count?
I would think so, yes. If I take a piece of information and do something to it inside my house, that's my business. If I show it to my friend, it's between him and me. If it let my coworkers see it so that they can only see it within the office, it's between them and me. And so on. The only issue would arise if an employee asked to see the source of such an internal tool and was denied.
The FSF FAQ explicitly states that internal use within a corporation does not count as distribution. It's one legal entity and can't violate copyleft on its own. A gray area would be a subsidiary or joint venture sharing with a parent.
That's really interesting, because if a corporation bought a physical book, scanned it, and distributed it internally that would be a clear violation of copyright law.
GPL is copyleft (copies authorized by default) until you violate the terms. Then normal copyright law applies and it's the same as an unauthorized book copy.
> The FSF FAQ explicitly states that internal use within a corporation does not count as distribution.
It's probably a good thing on balance since it's one less barrier to companies using code under the license, but considering companies and their assets (including their internal tools) can be bought and sold, I'd personally consider that distribution enough.
Your reasoning suggests the terms of the copyright license do apply when used as an internal tool (you'd be free to keep the code hidden otherwise) in which case preventing anyone from publishing any work derived from code under a copyleft license seems impossible. At the very least the GPL doesn't seem to allow you to create a derived work and require people to keep it secret even if it's just internal to the office (though I guess they could keep it secret willingly, I just see no way to legally compel them).
This seems different from something that's purely personal use. I don't think it makes much sense to force a program to show a notice its GPL licensed if you're the only one using it for instance. In fact that seems to run counter to the intent of free software.
It's possible that legal systems treat this situation differently, but I think it makes far more sense if you don't need an additional license to use stuff that's already published by the copyright holder until what you're doing starts to go beyond just personal use.
Of course; those are freedoms 0 and 1 guaranteed by the license. It seems like "use" sometimes means "include in a downstream software package and redistribute modified versions of".
Right, GPL only requires contributing forward, to the downstream users. It is only through creating a culture of working upstream and or reaching out to downstream redistributors that a project gets any contributions back, including financial contributions.
