Is the GPL actually viral across dynamic linking?

Posted Nov 19, 2024 1:25 UTC (Tue) by dvdeug (subscriber, #10998)
In reply to: Is the GPL actually viral across dynamic linking? by Wol
Parent article: Two approaches to tightening restrictions on loadable modules

> that linking is still done by the END USER

This is irrelevant. You can not distribute a sequel to someone else's book, because it's a derivative work. What makes code legally a derivative work of other code? There hasn't been a lot of case law about it, but I'd certainly argue that new code that intricately connects to data structures and functions in old code, in a way that's very distinctive, would be a derivative work.

> As far as I'm concerned, it is. If I GPL my code, downstream cannot distribute it as object without binary, but if their code calls mine, they can use any licence they like ... BECAUSE it's the end user that does the act of linking!

But that's your code. The idea that proprietary software does and can block any such thing, often going to the extents of having end users sign huge EULAs, but free software can't restrict itself being used as part of another non-free program.

Is the GPL actually viral across dynamic linking?

Posted Nov 19, 2024 9:23 UTC (Tue) by Wol (subscriber, #4433) [Link] (4 responses)

> > that linking is still done by the END USER

> This is irrelevant.

It's actually very relevant. It means dynamic linking *itself* CANNOT be a copyright infringement.

> You can not distribute a sequel to someone else's book, because it's a derivative work. What makes code legally a derivative work of other code? There hasn't been a lot of case law about it, but I'd certainly argue that new code that intricately connects to data structures and functions in old code, in a way that's very distinctive, would be a derivative work.

And THIS is the point. Is your work a derivative of the other work! Nothing to do with dynamic linking at all!

Or are we both arguing the same thing without realising it?

Cheers,
Wol

Is the GPL actually viral across dynamic linking?

Posted Nov 19, 2024 21:35 UTC (Tue) by nix (subscriber, #2304) [Link] (3 responses)

You seem to think that "derivative work" and whether something is a derivative work of something else is defined by the license. It's not: that would be an easy get-out and would make copyright licenses useless. Licenses cannot decree such things.

It's defined by the law, and more generally defined by courts when cases go to court: a license only says what happens if something *has been decided to be* a derivative work of something covered by that license. (In the UK it is almost entirely defined by reference to precedent: Parliament hasn't ruled on this stuff much. In the US I believe things are quite different: US law is much more about fiddly nailing-down-of-tiny-details, where UK law goes in for broad swaths and letting courts decide the fine details in ways that make sense at the time, and then letting precedent force consistency in future.)

Is the GPL actually viral across dynamic linking?

Posted Nov 19, 2024 22:21 UTC (Tue) by Wol (subscriber, #4433) [Link]

> You seem to think that "derivative work" and whether something is a derivative work of something else is defined by the license. It's not: that would be an easy get-out and would make copyright licenses useless. Licenses cannot decree such things.

Where did I say (or even imply) that? What is a derivative work is, as you say, a matter of (vague) law.

Go back to what I *did* say - that "dynamic linking can NOT be a GPL copyright violation, because the GPL *explicitly* permits it" (unless someone can come up with a scenario where the linking does not happen on the end user's machine - I can't!).

Distributing a program that abuses a GPL API can be a copyright violation, but that's not down to the end user, and that's not dynamic linking, and it's not a violation if the "abuser" does it on their own machine ...

Cheers,
Wol

Is the GPL actually viral across dynamic linking?

Posted Nov 20, 2024 2:15 UTC (Wed) by NYKevin (subscriber, #129325) [Link] (1 responses)

> US law is much more about fiddly nailing-down-of-tiny-details, where UK law goes in for broad swaths and letting courts decide the fine details in ways that make sense at the time, and then letting precedent force consistency in future.

You're thinking of European law. US (statutory) law absolutely does not nail down the fiddly little details of derivative works, it just gives a one-paragraph definition and lets the courts work it out:

> A “derivative work” is a work based upon one or more preexisting works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted. A work consisting of editorial revisions, annotations, elaborations, or other modifications which, as a whole, represent an original work of authorship, is a “derivative work”.

(17 USC 101)

Is the GPL actually viral across dynamic linking?

Posted Nov 20, 2024 12:28 UTC (Wed) by nix (subscriber, #2304) [Link]

I was actually getting it mixed up with other parts of the US legal code (particularly financial regulation), which very much do the "insane complexity and nail down every tiny rule". Too tired, shouldn't have been posting...