[SpicyLemonZest]

The FAQ is not at all clear about this question. #GPLInProprietarySystem says that you unconditionally cannot "incorporate GPL-covered software in a proprietary system", although it might be OK to ship a proprietary system that integrates with and depends on GPL software so long as "the two programs remain well separated". How do I know whether a particular API usage qualifies as well separated or not? The only standard described is "like the compiler and the kernel, or like an editor and a shell".

[camgunz]

> How do I know whether a particular API usage qualifies as well separated or not?

The two paragraphs above what you quoted are:

"However, in many cases you can distribute the GPL-covered software alongside your proprietary system. To do this validly, you must make sure that the free and nonfree programs communicate at arms length, that they are not combined in a way that would make them effectively a single program."

"The difference between this and 'incorporating' the GPL-covered software is partly a matter of substance and partly form. The substantive part is this: if the two programs are combined so that they become effectively two parts of one program, then you can't treat them as two separate programs. So the GPL has to cover the whole thing."

Two programs communicating over a socket aren't incorporated. They're two programs.

[SpicyLemonZest]

Again, the FAQ says otherwise. #MereAggregation says that this is "normally" the case, but "if the semantics of the communication are intimate enough" two binaries communicating over a socket may still be one program. Whether they are one program is explicitly left as a question for judges to decide.

[camgunz]

Here's how that section starts: "An “aggregate” consists of a number of separate programs, distributed together on the same CD-ROM or other media.". Are you distributing a lot of apps on CD-ROMs? Have you heard of Linux distributions? Seems like things are fine!

I'm not super interested in fielding more thin gotchas based on out of context quotes. There's a big difference between a license that's difficult to understand and a license that somehow summons people from the ether who find endless ways to deliberately misunderstand it.

[g15jv2dp]

Sorry but what does "arms length" mean? My software doesn't have arms. Using metaphors full of imagery is cute but essentially meaningless.

> Two programs communicating over a socket aren't incorporated. They're two programs.

Aren't they? So, if I want to use a GPL library, all I need to do is write a little wrapper program that does RPC over a socket, and boom, I can use a GPL library in my closed source program? Obviously not.

[camgunz]

> Aren't they? So, if I want to use a GPL library, all I need to do is write a little wrapper program that does RPC over a socket, and boom, I can use a GPL library in my closed source program?

Yep. This is how MySQL/MariaDB work, for example.

[pimeys]

What about when running a wasm component in an AGPL host? Can the compiled wasm file be proprietary? They share the same memory space, but the wasm component is not compiled with the host.

[camgunz]

Interesting; this sounds to me like linking, but I'd email [e-mail] to be sure.