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bundling GPL'ed contents with non-GPL materials

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Re: bundling GPL'ed contents with non-GPL materials

Postby erik » Thu May 12, 2016 11:39 am

The GPL is actually quite clear, if you add GPL code to your project your project should be GPL.
This is different for LGPL, but FGData and FGAddon are both GPL (which does not mean there could be LGPL'ed Nasal libraries in FGData or FGAddon).

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Re: bundling GPL'ed contents with non-GPL materials

Postby Hooray » Thu May 12, 2016 11:48 am

erik wrote in Thu May 12, 2016 11:39 am:The GPL is actually quite clear, if you add GPL code to your project your project should be GPL.


Sorry, that's wrong, or at least fairly inaccurate: it solely depends on the form of linking taking place, i.e. for what you wrote to be true, the GPL code would need to be linked into the same address space (e.g. binary/executable) of the other code, as long as it is using a form of RPC/IPC or another decoupled interface (think CLI, CGI), you can legally circumvent the GPL, which is why developments like HLA are going to make it extremely straightforward to just disable the GPL in its entirety, and which is why people have come up with the the Affero GPL to close that loophole.

Thus, "project" is too broad a term to make that statement valid, unless you automatically define project as being "a compiled piece of source code that executes GPL'ed code in the same address space".


http://www.gnu.org/licenses/gpl-faq.en. ... tarySystem
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 non-free 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.

If the two programs remain well separated, like the compiler and the kernel, or like an editor and a shell, then you can treat them as two separate programs—but you have to do it properly. The issue is simply one of form: how you describe what you are doing. Why do we care about this? Because we want to make sure the users clearly understand the free status of the GPL-covered software in the collection.

If people were to distribute GPL-covered software calling it “part of” a system that users know is partly proprietary, users might be uncertain of their rights regarding the GPL-covered software. But if they know that what they have received is a free program plus another program, side by side, their rights will be clear.
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Re: bundling GPL'ed contents with non-GPL materials

Postby bugman » Thu May 12, 2016 12:54 pm

I haven't corrected the draft yet, Hooray ;)

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Re: bundling GPL'ed contents with non-GPL materials

Postby erik » Thu May 12, 2016 1:58 pm

Hooray wrote in Thu May 12, 2016 11:48 am:
erik wrote in Thu May 12, 2016 11:39 am:The GPL is actually quite clear, if you add GPL code to your project your project should be GPL.


Sorry, that's wrong, or at least fairly inaccurate: it solely depends on the form of linking taking place, i.e. for what you wrote to be true, the GPL code would need to be linked into the same address space (e.g. binary/executable) of the other code


We're talking about scripts in FlightGear right?
Then this is always true at this time.

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Re: bundling GPL'ed contents with non-GPL materials

Postby Hooray » Thu May 12, 2016 2:03 pm

bugman's point about the GPL and JavaScript still holds true, and nicely maps to the problem we're talking about here.
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Re: bundling GPL'ed contents with non-GPL materials

Postby Thorsten » Thu May 12, 2016 2:31 pm

I haven't corrected the draft yet, Hooray


The wording sort of pre-supposes it'd be wrong now (allow me some skepticism... so far all suggestions were semantics or made certain aspects more precise, but didn't really point out anything outright wrong). But if you think so, we're happy to discuss your evidence. :-)
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Re: bundling GPL'ed contents with non-GPL materials

Postby Hooray » Thu May 12, 2016 3:09 pm

To point something that seems to be wrong:

A Nasal script that calls the Canvas rendering
framework is a derivative work of the Canvas rendering framework, which is
GPL'd, so the Nasal script must be GPL'd too. However, a Nasal script as
such (i.e. one that does not call GPL licensed Nasal code) is considered
data for the Nasal interpreter and does not trigger the license.


The Canvas system stopped being GPL when TheTom re-licensed all his work under the LGPL so that it could be moved to SimGear, which is LGPLed (see the archives/commit logs for reference).

However, interestingly, that does not apply to the scripting space FlightGear bindings exposed via the cppbind level or the fgdata wrappers, according to the headers :-)
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Re: bundling GPL'ed contents with non-GPL materials

Postby Thorsten » Thu May 12, 2016 5:09 pm

It's canvas.nas which is the issue here. My understanding is that if you use canvas via setprop(), then you're not bound by the license, if you go through canvas.nas you are.
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Re: bundling GPL'ed contents with non-GPL materials

Postby Hooray » Thu May 12, 2016 5:22 pm

legally, that argument is sound, because the equivalent of setprop()/getprop() can also be executed outside the fgfs process space, e.g. using telnet and/or Phi (mongoose/remote properties), i.e. you could create/update and control a MFD/Canvas using just the property interface, if you'd want to do that is a totally different story, i.e. there's more than just canvas.nas involved here, because there actually is a canvas namespace that is created, and populated, regardless of canva.nas - by C+ code exposing FG/SG classes, and objects, to Nasal and vice versa - using the cppbind framework.
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Re: bundling GPL'ed contents with non-GPL materials

Postby erik » Sun Jun 26, 2016 2:10 pm

While searching for a 7-segemtn display font I was introduced to the Open Font License (OFL) which includes an interesting clause:

http://scripts.sil.org/cms/scripts/page ... id=OFL_web
PERMISSION & CONDITIONS

Permission is hereby granted, free of charge, to any person obtaining
a copy of the Font Software, to use, study, copy, merge, embed, modify,
redistribute, and sell modified and unmodified copies of the Font
Software, subject to the following conditions:

1) Neither the Font Software nor any of its individual components,
in Original or Modified Versions, may be sold by itself.


2) Original or Modified Versions of the Font Software may be bundled,
redistributed and/or sold with any software, provided that each copy
contains the above copyright notice and this license. These can be
included either as stand-alone text files, human-readable headers or
in the appropriate machine-readable metadata fields within text or
binary files as long as those fields can be easily viewed by the user.

...

This could be used by people who are concerned about others selling their work. You could even extend it to deny including it in non-GPL licensed software.

The Free Software Foundation sees this as a free license:

https://en.wikipedia.org/wiki/SIL_Open_Font_License
The license is considered free by the Free Software Foundation, which states that a simple hello world program is enough to satisfy the license's requirement that fonts using the license be distributed with computer software when selling them.

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Re: bundling GPL'ed contents with non-GPL materials

Postby bugman » Sun Jun 26, 2016 4:15 pm

Here is the full FSF statement:

Various Licenses and Comments about Them#SIL Open Font License 1.1
The Open Font License (including its original release, version 1.0) is a free copyleft license for fonts. Its only unusual requirement is that when selling the font, you must redistribute it bundled with some software, rather than alone. Since a simple Hello World program will satisfy the requirement, it is harmless. Neither we nor SIL recommend the use of this license for anything other than fonts.

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Re: bundling GPL'ed contents with non-GPL materials

Postby erik » Sun Jun 26, 2016 4:25 pm

The trick is you can 'sell it when bundled' but not 'sell it by itself' which might give some users exactly what they want. You could even make it 'sell it when bundled with GPL licensed software but not otherwise.'

I hadn't seen such a clause before.

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