A new Flight Simulator

[IAHM-COL]

https://www.gnu.org/licenses/gpl-faq.ht ... cVsDynamic

Does the GPL have different requirements for statically vs dynamically linked modules with a covered work? (#GPLStaticVsDynamic)
No. Linking a GPL covered work statically or dynamically with other modules is making a combined work based on the GPL covered work. Thus, the terms and conditions of the GNU General Public License cover the whole combination. See also What legal issues come up if I use GPL-incompatible libraries with GPL software?

https://www.gnu.org/licenses/gpl-faq.ht ... uleLicense

If I add a module to a GPL-covered program, do I have to use the GPL as the license for my module? (#GPLModuleLicense)
The GPL says that the whole combined program has to be released under the GPL. So your module has to be available for use under the GPL.

But you can give additional permission for the use of your code. You can, if you wish, release your module under a license which is more lax than the GPL but compatible with the GPL. The license list page gives a partial list of GPL-compatible licenses.

https://www.gnu.org/licenses/gpl-faq.ht ... braryIsGPL

If a library is released under the GPL (not the LGPL), does that mean that any software which uses it has to be under the GPL or a GPL-compatible license? (#IfLibraryIsGPL)
Yes, because the program actually links to the library. As such, the terms of the GPL apply to the entire combination. The software modules that link with the library may be under various GPL compatible licenses, but the work as a whole must be licensed under the GPL. See also: What does it mean to say a license is “compatible with the GPL”?

[bomber]

Then I think you need to define what a module is with regards this endevour...

[bomber]

If a program combines public-domain code with GPL-covered code, can I take the public-domain part and use it as public domain code?

Interesting that this is a frequently asked questuon.... How can there be such a thing with your line of interpretation..

https://www.gnu.org/licenses/gpl-faq.ht ... ainWithGPL

[bomber]

What is the difference between an “aggregate” and other kinds of “modified versions”?

So it's quite clear that a 3D file provided by a 3rd party to be called up by the core flight sim code and used as data input to be rendered by the visual system is not a part of the flight sim code.

Neither for that matter is the texture which could be supplied by many different authors to be applied into the 3D model.

The Flight model xml contains only data that the GPL'd JSBsim program calls upon.

There is no direct communication between the 3d and the flight model.

https://www.gnu.org/licenses/gpl-faq.ht ... ggregation

[bomber]

I'd like to incorporate GPL-covered software in my proprietary system. I have no permission to use that software except what the GPL gives me. Can I do this?

This i feel is an important question...

At the start of the answer it seems like the answer is no, yet as you read on its quite clear it is not as simple as that. Understanding that the 3D, 2D, flight model, sounds ie the data of a plane have no relationship with each other and only communicate with the core flight sim program at arms length via the .set file makes it quite clear that in our case the answer is yes...

However it's also made clear that having clear communication with the user to ensure they know exactly what they're getting and their rights is paramount.

https://www.gnu.org/licenses/gpl-faq.ht ... tarySystem

[bomber]

For me though this conversation is about what do YOU want...

If you want all files to be GPL licence, then say so.

If you're prepared to have mixed licence planes, allowing all to contribute and protect their work as they see fit.... Then say so and stand by it.

There's an element of law involved here but also an element of the rules with which we agree to contribute to this new sim..

Make a rule and stick to it, then everybody knows where they stand.

[IAHM-COL]

I'd like to incorporate GPL-covered software in my proprietary system. I have no permission to use that software except what the GPL gives me. Can I do this?

This i feel is an important question...

At the start of the answer it seems like the answer is no, yet as you read on its quite clear it is not as simple as that. Understanding that the 3D, 2D, flight model, sounds ie the data of a plane have no relationship with each other and only communicate with the core flight sim program at arms length via the .set file makes it quite clear that in our case the answer is yes...

However it's also made clear that having clear communication with the user to ensure they know exactly what they're getting and their rights is paramount.

https://www.gnu.org/licenses/gpl-faq.ht ... tarySystem

Yes. Which is precisely the point. The GPL code cannot be legally, nor safely, nor it is ok to be distrubuted combined or aggregated with the non-GPL content.

from your link:

You cannot incorporate GPL-covered software in a proprietary system. The goal of the GPL is to grant everyone the freedom to copy, redistribute, understand, and modify a program. If you could incorporate GPL-covered software into a nonfree system, it would have the effect of making the GPL-covered software nonfree too.

A system incorporating a GPL-covered program is an extended version of that program. The GPL says that any extended version of the program must be released under the GPL if it is released at all. This is for two reasons: to make sure that users who get the software get the freedom they should have, and to encourage people to give back improvements that they make.

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.

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.

Back to interpretations: I think this answer is in line with my interpretation quite well

1. No. We cannot safely aggregate or combine codes of free and non-free licenses. That is, we cannot make a plane by aggregating content with GPL and content non-GPL.

2. Yes. We can safely provide a GPL core and content, and then addons. If these addons extend features or provide feature that are in addition to the functionality of the program and content then these addons can be distributed in isolation, and in absentia of ANY of the GPL core code and content. These addons licenses can be of any nature, and ultimately it would be an independent agreement between users and the extension authors to agree on their licensing terms.

[IAHM-COL]

For me though this conversation is about what do YOU want...

If you want all files to be GPL licence, then say so.

If you're prepared to have mixed licence planes, allowing all to contribute and protect their work as they see fit.... Then say so and stand by it.

There's an element of law involved here but also an element of the rules with which we agree to contribute to this new sim..

Make a rule and stick to it, then everybody knows where they stand.

What would I like?

pyFS => a new flightsimulator python-powered
Core: Licensed under GPL ver 3.0 or above
Modules interface: This would be a Library that exposes the core to the content. In other words code that makes possible adding content by installing modules/classes (read modules/classes in the pythonic way. Licensed under LGPL ver 3.0 or above
==> Note. The Modules interface by being LGPL allows dynamic linking to content of Any license
Content (scenery/aircrafts): This would be functional units that link throught the modules interface to the core.Example an aircraft, and WITH ALL of its functional parts, including but not limited to 3d models, sounds, effects (model rendering, sound rendering, animations, instruments rendering and animations, etc), systems, FDMs, liveries. These contents can be licensed either GPL, LGPL, or any other non-free license. Ideally, lots of it would be LGPL; but this is clearly not what needs to occur. Necesarily at least some content needs to exist GPL or LGPL otherwise the simulator wouldn't fly free.
Content extension: This would be addons that link to content via the Modules interface. Like per example a new FDM or FDMs collection for a given plane, a new 3d model (or models) for a given plane, a collection of models, animations and systems for a new airport scenery, a new sound package or collection of them. These addons or extensions licenses could be either GPL, LGPL or any other non free license

The important thing about content and content extensions above is that they do not need to attempt to bundle the GPL of the core, nor the LGPL of the Modules interface, nor the GPL or LGPL code and data of the Free content. Instead would be content effectively isolated, that is just linked dynamically via the modules interface. In other words, to offer a new, lets say, CC-NC livery package for a GPL aircraft, one does not need to bundle the aircraft with it, making a complex situation between the non-compatible provisions of the CC license with the GPL. All this needs is the paintjob, the livery files, and a config that interfaces these with a given plane or planes thru the Module interface. All these content would then just be installed alongside (*but not within*) the simulator, and then become selectable (for usage) thru the pyFS menu.

The clear separation and distintion and the posibility of legally making dynamic linkings between the GPL/LGPL code and content and new Non-GPL content is what I think we could strive for.

On the contrary, suggesting that's ok to create bundled content where each file can or may have licenses of their own, I think this would be, in my opinion a no=go.

[bomber]

Ok how I understand it is that having written a bit of software and licencing it GPL. Another person then can't take that code and add to it new lines of code and think these new lines can be another licence.

Neither can a person take lines of GPL code and add it to their proprietory code...

Or for that matter take the GPL code and add to it a line that calls up a separate file of code but licence this file differently, as quite clearly this is just an extension of the first GPL code and not two separate parts.

It's about theft... Stealing another person's work...

I won't do that.

But neither will I prevent another person from contributing to a plane with a separate piece of work covered by the licence that they wish.

As I said it's about theft....

I commit no crime, and GPL is not a virus... But it is used by people with the same thinking as yourself to prevent mixed licence collaborations which hurt or take from no one.

[bomber]

When I worked on tartgetware, we simply licenced our content as noncommercial that could be copied, modified and distributed for use with in Targetware flightsim only in perpetuity.