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The GNU GPL license and unwritten rules of curtesy

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Re: The GNU GPL license and unwritten rules of curtesy

Postby Thorsten » Wed Aug 19, 2015 4:31 pm

The simple reason is because the GPL is, as someone famous once said, like a cancer. It spreads to everything it touches.


Except when it doesn't because you just bundle it, you don't depend in any way on GPL stuff. Which is why GPL compatible stuff bundled with GPL doesn't become GPL but remains GPL compatible, and public domain bundled with GPL remains public domain. Which really were impossible if what you claim would be strictly true.

But then again, you also argued one can't really bundle with GPL compatible stuff either, so your interpretation of how GPL works is a bit unique.
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Re: The GNU GPL license and unwritten rules of curtesy

Postby Johan G » Wed Aug 19, 2015 4:42 pm

bugman wrote in Wed Aug 19, 2015 2:35 pm:Using copyright and GPL language - I believe that the aircraft and all its parts would be classified as a "whole" work, and therefore licence compatibility for all components is essential.

Thorsten wrote in Wed Aug 19, 2015 2:56 pm:It seems easy to argue that an FDM running under multiple different contexts hence doesn't have to be a whole and doesn't have to have a unique license if I can attach it to either FG or Outerra. It seems also easy to demonstrate that FG pretty readily allows to attach several different FDMs to a single plane. Which is to say the components are not interdependent but modular and are hence not a whole.

bugman wrote in Wed Aug 19, 2015 3:46 pm:Firstly, although a lot of my experience is with GPLed software products, this software consists of ~80% data, graphics, and other multimedia. The GPL can be applied to this content as well, and it will not receive any special treatment under under copyright law.
...
Rather I was talking about the combination of the FDM XML file with the AC3D file, sound files, liveries, etc. This combination is a bundle, and this bundle would be considered a "whole" work. Each part cannot operate in isolation. If you take someone's 3D GPLed model, rip out the YASim FDM and add a JSBSim FDM, but licence the new FDM with a non-GPL compatible licence (CC-BY-NC, commercial, etc.), you would likely be in trouble. This simply cannot be done.

I am not so sure. Really, the only thing binding the 3D model, FDM and other stuff together is the configuration files (for example the aircraft-set.xml, animation and sound xml configuration files etc).

In essence you could "easily" replace one FDM with a scratch built other one. The same goes for the 3D model, sounds and systems. And yes, even liveries (after all, the liveries sometimes are better references to model a new aircraft 3D model after than the 3-view drawings that was used in the first place :wink: ).

For example, there have been many instances when an FDM have been replace by an entirely new one. As far as I consider, the main reason the FDM is released with the same license as the package/bundle usually (so far always?) is mere convenience.

At the other hand, distributing the entire package with a new license, even after some major changes, is another thing all together though, but I think/hope we all agree on that though. :wink:
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Re: The GNU GPL license and unwritten rules of curtesy

Postby Jabberwocky » Wed Aug 19, 2015 5:47 pm

Well well well, everybody is so smart and when someone says something that doesn't fit their "smartness" they assume, the other one never read the license or is just plain old stupid. But in fact, it is very simple. Try it and if you get sued and ruined, you know, I was right.
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Re: The GNU GPL license and unwritten rules of curtesy

Postby bugman » Wed Aug 19, 2015 5:48 pm

Thorsten wrote in Wed Aug 19, 2015 4:23 pm:
This combination is a bundle, and this bundle would be considered a "whole" work. Each part cannot operate in isolation


I assure you an FDM can operate perfectly fine in isolation, having zero dependence on the 3d model. Which is precisely why I argued that they're not interdependent but modules which can be used alone or in isolation or swapped against other modules (even at runtime). So there's just no reason at all to think a bundle of demonstrably independent modules would be considered a whole by anyone except yourself.


I am aware of this, when I started using FG back in 1998, that's all there was. These still exist, see $FG_ROOT/Aircraft-uiuc/ for example. But once bundled with other components, this has a legal effect. The bundling of aircraft components together (FDM, 3D, sound, Nasal) to create a whole aircraft which is distributed as a single unit is not much different from bundling the FG code components together (FG, simgear, all FDMs, Nasal, MP, etc.) to create a whole - licence compatibility issues must be considered.


Thorsten wrote in Wed Aug 19, 2015 4:23 pm:
Firstly, although a lot of my experience is with GPLed software products, this software consists of ~80% data, graphics, and other multimedia. The GPL can be applied to this content as well, and it will not receive any special treatment under under copyright law.


Unlike GPL, copyright law is mostly not concerned with code but with artwork, so your statement doesn't make too much sense - nobody said GPL doesn't apply, and Artwork is in practice treated differently from code under copyright law - the threshold of originality in the cases I have seen is very much lower. And needless to say, lots of GPL provisions don't make too much sense for artwork - hard to hide the source of a JPEG file.


True, but the point of this this was simply to point out that I have licensed non-code content under the GPL and am aware of the implications, as it includes works copyrighted by multiple authors and other non-GPL, yet GPL compatible content.


Thorsten wrote in Wed Aug 19, 2015 4:23 pm:But, well, let's not forget that last time we discussed copyright you claimed corporations are out there to get us and using poorly defined licenses as traps, that US copyright law wouldn't necessarily be relevant for something that happens on the US-based SourceForge server and that fair use can't be used for much in practice despite several prominent court cases to the opposite, so forgive me if I take your claim about a bundle of independent modules being a whole with more than a grain of salt.


My aversion to copyright licensing legal issues, avoiding these grey issues as much as possible for the FG project, and keeping everything separate, clean and thereby avoiding mixing and any resultant legal issues, cannot in any way be construed as me saying that "corporations are out there to get us". Avoidance and staying on the safe side is quite a different perspective. I also didn't say that US copyright law doesn't apply, just that it and it's fair use provisions would have zero relevance to a legal case in brought in Hamburg, for example.


Thorsten wrote in Wed Aug 19, 2015 4:31 pm:
The simple reason is because the GPL is, as someone famous once said, like a cancer. It spreads to everything it touches.


Except when it doesn't because you just bundle it, you don't depend in any way on GPL stuff. Which is why GPL compatible stuff bundled with GPL doesn't become GPL but remains GPL compatible, and public domain bundled with GPL remains public domain. Which really were impossible if what you claim would be strictly true.

But then again, you also argued one can't really bundle with GPL compatible stuff either, so your interpretation of how GPL works is a bit unique.


Where did I argue this? If you look back at what I said, in this case I was talking about merging GPL and non-GPL into a single file, not bundling separate files as one whole. I think there might be a mix up of licence compatibility issues and the FG policy document discussions for FGAddon. There I mentioned that it looked like the old policy was GPL-only, except for the 3rdparty/ directories which is where GPL compatible code is located (and, of course, the LGPL libraries such as Simgear). But that if changed to have GPL compatibility for all components, that the licensing implications and intricacies be made crystal clear.

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Re: The GNU GPL license and unwritten rules of curtesy

Postby Thorsten » Thu Aug 20, 2015 2:41 pm

Let's try a reductio ad absurdum, shall we?

X makes a very impressive ac3d model + livery of an Airbus A-380. Now X puts this out on his commercial page as

a) 3d model of Airbus A-380 for sale - 10$ and you can use it for whatever you like

b) adds a note: by the way, you can use this for the GPL simulator Flightgear or for X-plane

c) adds an instruction how to add it to FG or X-plane

d) gives a download link for you convenience, here is my 3d model ready to use in Flightgear as per the instruction above

At which point does this become illegal? When he tells someone how to copy it into an FG folder? Or when he actually does the copying (heavens present!) himself? Or perhaps never, because it doesn't make any sense?

It is very clear in all cases that the thing being sold is only a 3d model - which has FG as a potential use case, but others as well. It is also very clear that while a JSBSim FDM can be used in FG, it doesn't have to be - it can be used in JSBSim standalone, it can be used in Outerra, and in fact in any simulation anyone codes using JSBSim.

So your claim is that either the act of copying two files (which have been independently created and have no technical link between each other) next to each other or even the mere potential of doing so warrants a GPL claim (we seem to agree that you can run commercial licensed things in a GPL environment).

And I doubt that claim. I can copy commercially licensed programs or addons into my Linux folders just fine. I can copy free MP3 next to copyrighted. I can tell someone 'you may copy this subfolder, but not the other because they have a different license'.

You can claim that I am bound by the GPL license if I use a GPL'ed file to create some other content. But you can't claim the same thing if I execute GPL and non-GPL content next to each other in the same environment or have them resting in different subfolders inside a folder on my harddisk.

I am fairly sure you could get the 3d model developer if he would try to sell the whole package as a commercial product. But as long as he points out what is being sold and doesn't try to mix licenses? It's hard to construe a bundling intention if he points out that the things are licensed differently. Differently licensed files can in principle co-exist in the same project, we have ample proof of that. You're buying a 3d model. Simon is making an FDM. While they can be used with FG, their use is not limited to that. While they can be used next to GPL content, they in no way depend on GPL content. The mere act of copying stuff in a subdirectory doesn't equal a usage that would trigger GPL.
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Re: The GNU GPL license and unwritten rules of curtesy

Postby bugman » Thu Aug 20, 2015 3:40 pm

Thorsten wrote in Thu Aug 20, 2015 2:41 pm:Let's try a reductio ad absurdum, shall we?

X makes a very impressive ac3d model + livery of an Airbus A-380. Now X puts this out on his commercial page as

a) 3d model of Airbus A-380 for sale - 10$ and you can use it for whatever you like

b) adds a note: by the way, you can use this for the GPL simulator Flightgear or for X-plane

c) adds an instruction how to add it to FG or X-plane

d) gives a download link for you convenience, here is my 3d model ready to use in Flightgear as per the instruction above

At which point does this become illegal? When he tells someone how to copy it into an FG folder? Or when he actually does the copying (heavens present!) himself? Or perhaps never, because it doesn't make any sense?


Clearly, est absurdum! This is not illegal, because the GPL and other open source licences only apply to the distribution of content. You can distribute one part under a non-GPL compatible licence - as the above example is - and tell the end user to combine it with GPL or CC components.

But what does this have to do with bundling multiply licensed content as one download, in FGAddon for example? This absurdum person would not be able to include the GPL or CC components from FG in their $10 download. Can I reduce the reductio ad absurdum even future to mean that you are saying that the differently licensed components should be distributed separately?

Regards,

Edward
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Re: The GNU GPL license and unwritten rules of curtesy

Postby bugman » Thu Aug 20, 2015 4:00 pm

Thorsten wrote in Thu Aug 20, 2015 2:41 pm:The mere act of copying stuff in a subdirectory doesn't equal a usage that would trigger GPL.


This GPL (or CC or other open source licence) situation depends on 3 factors:

    Who is doing the bundling;
    License compatibility;
    And if everything can be considered a "whole" or a bundle of unlinked, independent components.

Let us assume licence incompatibility and that this is a "whole". If it is the end user assembling everything together, the person distributing the GPL incompatible component is not at fault. But if it is the distributor performing the bundling, then it is simple - there is a licence violation and they cannot legally distribute the GPL part. For the last assumption of a "whole", the XML files links everything together and it is loaded into FG as a single unit. The purpose of the bundle is to be used as a single interdependent unit.

Regards,

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Re: The GNU GPL license and unwritten rules of curtesy

Postby Thorsten » Thu Aug 20, 2015 4:37 pm

In the rest of the world, (non)-dependency is testable rather simply by brute force:

A is dependent on B if

* B has been used or was necessary to create A
* B is necessary to use A, i.e. A no longer functions if I remove B

Both conditions are wrong for the connection between FDM and 3d model. I do not need a 3d model to create an FDM, and I can remove the 3d model loading time or runtime and still get a meaningful FDM behaviour. Good luck getting around logic.

Let us assume licence incompatibility and that this is a "whole"


Let us assume you are right, then it follows that you are right. However, let us start from the assumption that you are in fact wrong, and you will find that you are wrong. This is a mere play with words, since the whole thrust of my argument is that a collection of non-dependent modules is not a whole.

Btw, even if you were right, you still couldn't force anyone to license GPL - all you could accomplish is that they remove the GPL content from their bundle.

In any case, I think this argument is rapidly becoming fruitless. You started from the claim that an FDM requires a 3d model, the claim was disproven, now you try to re-introduce the claim by assumption. Sorry, try someone else. I haven't seen anything that argues that a collection of separate modules which are identified as such and not sold/advertized as a whole is a whole, and I haven't seen anything that could force anyone to license his work GPL if it never used GPL during its creation.

For the last assumption of a "whole", the XML files links everything together and it is loaded into FG as a single unit.


A single unit? Dream on. The FDM is handed to JSBSim, the 3d model to OSG. FG is just as modular in its design. They're not loaded by the same code, not even by code licensed the same way.

If I write a batch shell script starting Photoshop and Gimp at the same time, does that also make them a single unit? Seems a cool way of forcing Photoshop into GPL domain...
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Re: The GNU GPL license and unwritten rules of curtesy

Postby bugman » Thu Aug 20, 2015 5:08 pm

This is better, the argument has narrowed down to a single question. In GPL terms is a FG aircraft - which is distributed with all its components - a "whole" or a "mere aggregation"? Then the relevant information is:


This states:

What is the difference between “mere aggregation” and “combining two modules into one program”?

Mere aggregation of two programs means putting them side by side on the same CD-ROM or hard disk. We use this term in the case where they are separate programs, not parts of a single program. In this case, if one of the programs is covered by the GPL, it has no effect on the other program.

Combining two modules means connecting them together so that they form a single larger program. If either part is covered by the GPL, the whole combination must also be released under the GPL—if you can't, or won't, do that, you may not combine them.

What constitutes combining two parts into one program? This is a legal question, which ultimately judges will decide. We believe that a proper criterion depends both on the mechanism of communication (exec, pipes, rpc, function calls within a shared address space, etc.) and the semantics of the communication (what kinds of information are interchanged).

If the modules are included in the same executable file, they are definitely combined in one program. If modules are designed to run linked together in a shared address space, that almost surely means combining them into one program.

By contrast, pipes, sockets and command-line arguments are communication mechanisms normally used between two separate programs. So when they are used for communication, the modules normally are separate programs. But if the semantics of the communication are intimate enough, exchanging complex internal data structures, that too could be a basis to consider the two parts as combined into a larger program.


This suggests that the dependency test:

Thorsten wrote in Thu Aug 20, 2015 4:37 pm:A is dependent on B if

* B has been used or was necessary to create A
* B is necessary to use A, i.e. A no longer functions if I remove B


may be too stringent. For example the XML files connecting everything together -may- cause it to no longer be a "mere aggregation" (the XML file would be C in this test, which links A and B). The FG property tree is another concept which connects everything together. But that is really up to a court to decide, and a decision may go either way. And this point brings me back to my simple aversion of avoiding legal grey areas for the good of the project ;)

Regards,

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Re: The GNU GPL license and unwritten rules of curtesy

Postby Thorsten » Thu Aug 20, 2015 5:18 pm

We believe that a proper criterion depends both on the mechanism of communication (exec, pipes, rpc, function calls within a shared address space, etc.) and the semantics of the communication (what kinds of information are interchanged).


An aircraft-set.xml is a static data structure, not communication. If you like, the equivalent of a batch script - load this, load that, load that.

See, if crucial communication were exchanged between A and B, you would disable B by removing A. But in fact A remains completely unaffected by the absence of B. The 3d model doesn't communicate with the FDM at all. Which is why I can unload it runtime and nothing bad happens to the FDM - the FDM doesn't even notice. Which is also why I can load a completely different 3d model if I want to without changing the FDM.

So I can apply my criterion or the communication criterion, the conclusion doesn't change.

The FG property tree is another concept which connects everything together.


Well, if that were relevant, you could never run any non-GPL content in FG since it also ties weather and the environment into the simulation. But we just before agreed that FG is an environment in which things run and the general consensus seems to be that you can run non-GPL things inside a GPL environment.
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Re: The GNU GPL license and unwritten rules of curtesy

Postby Bomber » Thu Aug 20, 2015 5:31 pm

I'd make this easier and say that the plane as a whole is made up from differing files, of differing file formats requiring vastly different skills....

I'm a professional 3d modeller, but I'm not a 2d artist..... Two wildly different skill sets... And flight modelling is another story all to gather...

It's unreasonable to limit contribution within FG solely because the authors wish to protect their work against sources outside the FG community.

An agreement between authors and FG allowing lifetime use/modification/distribution within the FG community yet still retain protection against external misuse would resolve all internal FG conflict.

But maybe people just like infighting

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Re: The GNU GPL license and unwritten rules of curtesy

Postby bugman » Thu Aug 20, 2015 5:54 pm

Hi Simon,

For the official FlightGear policy document which will soon be published, everything should be clearer. The relevant draft text is:

Aircraft released under the GPL2+ may be hosted on the fgaddon repository, for which their author will receive commit rights. All contributions to fgaddon repository must be compatible with the GPL, and should include an AUTHORS file listing the copyright holders of the aircraft and a COPYING files containing the GNU General Public Licence V2.0 license text (http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt). Such aircraft are considered projects in their own right, but may receive updates from the core committers for bug fixes and compatibility with core changes. Aircraft authors must review all merge requests to their aircraft, provide feedback, and work with other contributors. If an author is no longer available, the aircraft may be maintained, adopted and improved by other contributors. The core committers will adjudicate on any disagreement and reserve the right to revoke commit rights.


Note, this may change a little before the final version is out. So if it is GPL-compatible, as defined by the FSF:


it can get into the official aircraft repository. Well, assuming that the licence is not somehow violated (for example by copying the file contents into another file with a different licence). There's nothing else to it. As for the diverse private hangars, they will likely have their own licensing policies, documented or otherwise.

Regards,

Edward
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Re: The GNU GPL license and unwritten rules of curtesy

Postby Bomber » Thu Aug 20, 2015 6:18 pm

Well I'm a member of FG community and I don't want that wording.....

As its draft it must be up for change
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Re: The GNU GPL license and unwritten rules of curtesy

Postby bugman » Thu Aug 20, 2015 6:24 pm

Bomber wrote in Thu Aug 20, 2015 6:18 pm:Well I'm a member of FG community and I don't want that wording.....

As its draft it must be up for change


It was discussed on the devel mailing list. I suggest reading the messages in that thread to get up to speed on the past discussions, and to know the opinions of others. If you'd like to contribute, you should sign up to the devel mailing list, if you haven't already. You would then be able to respond directly to old thread messages by using the "Followup" menu entry in the top right corner.

Regards,

Edward

Edit: Which wording don't you like?

Edit 2: For this, note the policy document wording:

All decisions affecting the core of the project (e.g. simgear/flightgear source code, fgdata, releases, infrastructure, future direction) are made on the flightgear-devel <at> lists.sourceforge.net mailing list, and those interested in the development of the project are strongly encouraged to subscribe. Participants on the mailing lists are expected to post using their real names and follow the principles above. Personal attacks, flame-wars, or other negative, non-constructive behaviour will not be accepted.
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Re: The GNU GPL license and unwritten rules of curtesy

Postby Bomber » Thu Aug 20, 2015 6:54 pm

It's not the core of the code we're talking about here it's content.....

there's a difference....
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