Open Source

[iamntz]

If you’re using GPL libraries in your application and distribute that application, you also need to distribute the source.

Don’t need to be in the same package, but you should make it accessible and let the users know they can do this.

As your main question:

Now, here’s my question… what happens if some of the plugins (be it plugins either created by the company or by users) use GPL dependencies… Would the GPL dependencies only affect to the plugin(s) or would also infect the host and other closed-source plugins?

The „infection” won’t spread, as the host author doesn’t have control on what you’re using. The author only exposes some APIs.

[BPL]

A while ago my question has been flagged as duplicate of this one:

Can plugins for closed source software use GPL'd libraries?

In the validated answer there you can see a bunch of related links to this topic:

• When is a program and its plug-ins considered a single combined program?
• If I write a plug-in to use with a GPL-covered program, what requirements does that impose on the licenses I can use for distributing my plug-in?
• Can I apply the GPL when writing a plug-in for a nonfree program?
• Can I release a nonfree program that’s designed to load a GPL-covered plug-in?
• You have a GPLed program that I’d like to link with my code to build a proprietary program. Does the fact that I link with your program mean I have to GPL my program?

Just for the record, I’m truly interested on this subject as I’ve got a plugin based software of mine and I’d like to protect it to get “infected” by potential 3rdparty GPL plugins (or plugins that use GPL deps).

Let me put a very concrete example in the context of Sublime, let’s consider whatever SublimeText GPL plugin… for instance, this one, which it’s distributed under the terms of the GNU GPL v3.

Now, could you please explain me how it’s SublimeText protecting itself to get infected on these cases?

[FichteFoll]

Sublime Text doesn’t need to “protect” itself at all because those third-party GPLed plugins don’t ship with it. The GPL cares about distribution rather than usage.

See also “the GPL rules only apply at distribution time”

[BPL]

Glad to hear, that sounds like common sense to me… just asking as these licenses are really tricky ones and it’s quite difficult to know all the intricacies . And just for the record, terms like “protect”, “infect”… I’m not opossed against open source software at all but it’d be great simple coders like me (and not just lawyers) could understand easily if our software could potentially violate some license clause or whatsoever…

And yeah, I’m already aware of both https://choosealicense.com/licenses/ and https://tldrlegal.com/ but even so…

[FichteFoll]

Anyway, to be precise: if the library you intend to use is GPLed and you want to distribute it with your plugin, your plugin also needs to be under the GPL.
If users can acquire the GPLed library from a separate entity (e.g. pip, npm, the Linux distro’S package manager, direct download from a library’s website), you don’t need to adhere to any restrictions of the GPL because it doesn’t apply.