GPLv3 license question for closed source games using Robust Toolbox

[PowerfulBacon]

In legal.md, code inside robust toolbox before 2019 is using GPLv3. Would this cause any issues for games made using robust toolbox that are commercial and closed source?

[FairlySadPanda]

PSA: not a lawyer, not a member of the Space Wizards team.

Sometimes a company does fall afoul of GPL. Sony Computer Entertainment, for example, has sometimes had to release code it either didn't realize was GPL'd.

You only need to be careful if someone has unwisely chosen AGPLv3. AGPLv3 projects are not open source and should be avoided.

On GPL itself, I originally wrote this comment before actually reading the GPL license again. My understanding regarding RT is that an RT game can be built and shipped without needing to bring in GPL as there's not much left of RT that's underneath it (a Space Wizards maint can probably confirm that).

[PowerfulBacon]

Thanks, the main issue here is the fact that some code is GPLv3 but all code after 2019 (built on the GPL code) is MIT. Worst case scenario, any edits to the game engine can just be included in an open-source fork but any game code would be a seperate project from the engine anyway so even in that case it wouldn't be a huge issue.

[FairlySadPanda]

In general just make sure that you make it clear what GPL code you used, how you use it and contribute changes to the GPL'd code back to RT if you'd like, otherwise distribute them under the same license. I don't think much of RT is still under GPL.

[FairlySadPanda]

For more information I really like Snyk's overview of each license and their handy chart. https://snyk.io/articles/what-is-gpl-license-gplv3-explained/

[0x6273]

Some of the authors agreed to license their GPL code as MIT, but I think not all of them did so there's likely some GPL code left still. You'd have to rewrite those parts or find the authors and ask them for a license, if you don't want your game to be subject to the GPLv3 license.

[PJB3005]

Some of the authors agreed to license their GPL code as MIT, but I think not all of them did so there's likely some GPL code left still. You'd have to rewrite those parts or find the authors and ask them for a license, if you don't want your game to be subject to the GPLv3 license.

This is basically correct. We got signoff from most people to relicense shit, and the people that we didn't don't have any code in the game anymore. The only exception to this area few stickler systems like PlacementManager (which need to be thrown out entirely anyways).

[FairlySadPanda]

@PJB3005 Is there a list somewhere of what's to do here, or is that itself a to-do?

[PowerfulBacon]

@PJB3005 Is there a list of which authors agreed to have their code relicensed to MIT? I see on the legal.md page it shows you, but no others. That would be useful for identifying which code is a derivative of GPL and needs replacing.

[benev0]

From reading old discord discussion this concern is not new; however, it is primarily a concern that external groups will harass closed source repos on the basis that the engine failed to change licenses. I was not able to find any evidence that there was a missing confirmation vote with the exception here.

There might not even be that much GPL code left. As far as I'm aware only PlacementManager is still GPL.

...

Some of the authors agreed to license their GPL code as MIT, but I think not all of them did so there's likely some GPL code left still. You'd have to rewrite those parts or find the authors and ask them for a license, if you don't want your game to be subject to the GPLv3 license.

This is basically correct. We got sign off from most people to re-license shit, and the people that we didn't don't have any code in the game anymore. The only exception to this area few stickler systems like PlacementManager (which need to be thrown out entirely anyways).

@juliangiebel and @PJBot please elaborate on what you mean.

The crux of the issue is without provisions in a CLA to allow for an org or a smaller group to alter the license, then every contributor holds the license and a source can can only alter its license under a unanimous decision. The nature of GPLv3 is that a source that includes GPLv3 code is GPLv3. Exceptions are made for dynamically linked libraries because the binary is not shipped with the GPLv3 content. That is software can dynamically link to GPLv3 binaries without also being GPLv3. Games that fully package the engine and content could be vulnerable to engine license issues, but any games that are hosted on the launcher will only face copyright issues for their content.

Realistically non-pre-changeover contributors don't have a way to dispute the license change.

Here is how to get a list of contributors:

git shortlog --summary --numbered --email --before"2019-3-14"

[PowerfulBacon]

From my understanding, any completely new code that doesn't derive from the GPLv3 code can be released under the MIT license while also being distributed under GPLv3. Only the combined work is under GPL, not the non-deriving code. I have no idea what counts as a derivative however, as its usually pretty broad in copyright law.

For now, I have decided to go with a different game engine as I have a rule to only introduce 1 major change at a time so introducing multiplayer and a new engine at the same time would violate that rule. I may come back to considering RT in the future if I have a game idea that at a low level functions in a similar vain to Space Station 13/14.

[0x6273]

GPLv3 means that IF YOU MODIFY the GPL'd code you need to distribute it under GPL (share-alike). However if you don't modify it, you obviously don't need to bother.

That's not at all how it works. GPLv3's copyleft would apply to the whole game.

[PowerfulBacon]

Yea, doing some googling and reading of the license seems to confirm this. Anything strongly linked using GPLv3 code also has to be GPLv3. That's presents pretty big issue

[FairlySadPanda]

Under GPL:
"A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an “aggregate” if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate."

You do not need to make everything that touches GPL code GPL.

That said I'm wrong enough on my original point I'll make edits. My fault for reading summaries before going and reading the license itself end-to-end.

[0x6273]

Did you even read what you just quoted?

[PowerfulBacon]

It would most likely be considered to be a combination with it to form a larger program in this case. It seems like if you need to include the source of the engine to interact with it, then that would almost certainly be a larger program and working around that would be difficult. If it was used by loading the assemblies via DLL and using it as an API then maybe the argument that it isn't forming a larger program would work. It would probably be easier at that point to find the old code that remains as GPL and rewrite it.

Robust toolbox seems like an excellent engine and provides a lot more than monogame in terms of networking out of the box, so I was hoping to see if it was viable to use for my next game since I'm looking for something more code based than editor based. I'll do some work to see how viable it would be to get rid of the GPL code by contacting the authors or rewriting certain parts of the code. It's just challenging since the code needs to not be a derivative of that GPL code and determing what MIT code is a derivative of GPL code could be extremely difficult.

[FairlySadPanda]

Did you even read what you just quoted?

Blame me being remoted in on a system, on a coffee break, remembering a conversation from three months prior!

I'm confident the remaining GPL code here is not enough of an issue; SS14 and a lot of downstreams have been happily chirping away for years. If there is any particular problem, considering I put my foot in it earlier I'd be happy to help remove any problematic code.

[0x6273]

You only need to be careful if someone has unwisely chosen AGPLv3. AGPLv3 projects are not open source and should be avoided.

This is also not true. AGPLv3 is an open source license.

[FairlySadPanda]

if you want to argue the osi are idiots dont use their definition like its gospel

OSI have a good definition I agree with, so it's worth sticking to definitions! We'd all go insane otherwise. Totally agree that forks being mandated as source-available and share-alike is mostly a good thing, because it prevents closed-source forks exploiting other people's work, at the cost of sometimes making it hard to collaborate.

[juliangiebel]

forks having to be open source is a good thing

That's GPL not AGPL. Panda claimed AGPL shouldn't be considered open source because it contradicts one of the definitions of what an open source license is

[deltanedas]

server code being gpl doesnt matter as you dont distribute the server - you connect to it

[FairlySadPanda]

GPL vs AGPL innit, really big difference

[PowerfulBacon]

server code being gpl doesnt matter as you dont distribute the server

Not all games want to have all their content delivered via the server, which makes it tricky when in a game engine that you are directly extending (unlike something like Unity where everything is loaded via scripts and you never touch any Unity code directly).