Is it possible to commercially release a game on OpenMW?

[DestinedToDie]

I've been reading the GNU GPL FAQ here: https://www.gnu.org/licenses/gpl-faq.en ... NUSoftware

Although dumbed down, it still feels kind of like lawyer-talk to me. In several instances, I see "yes, you can sell it".

However there's also stuff like this: https://www.gnu.org/licenses/gpl-faq.en ... GPLPlugins

From what I understand, OpenMW counts as a program. Game assets and .omwgame/omwaddons are files, and not actual programs. Or maybe I'm reading this wrong and that's not an issue at all.

Does the GNU GPL license make it possible to release a game that has data files copyrighted under a different license?

[charlieg]

In summary: yes, you can sell it. You just have to give access to any changes you have made to the source code. You could keep the assets commercially licensed.

There are GPL licensed programs where authors sell the binaries i.e. officially supported builds e.g. Ardour. You could technically take an existing open source project e.g. Super Tux Kart and sell it on Steam although it would be extremely unethical to do so and there would probably be compelling reasons for Steam/Valve to refuse it. I do recall somebody selling CDs of Flightgear, Super Tux Kart, and others on Ebay.

[psi29a]

Take a look at Torchlight, it uses Ogre3D as its game engine. That was originaly under LGPL at time of release (it is now MIT).

You can create your own content which is under your copyright, so you are in fact selling content that would run in/on an GPL based game engine. So long as you abide by the GPL with regard to OpenMW (engine), then you can sell the new game for whatever/however much you want.

Basically, if you modify OpenMW then you'll need to provide the sources. If you don't modify it, and use as-is then you can just link to OpenMW in your documentation.

Remember, your content is under your (de facto) copyright and has nothing to do with the GPL which is a license.

[DestinedToDie]

You can create your own content which is under your copyright, so you are in fact selling content that would run in/on an GPL based game engine.

Basically, if you modify OpenMW then you'll need to provide the sources. If you don't modify it, and use as-is then you can just link to OpenMW in your documentation.

Thanks! I just needed for someone to spell it out for me.

[Parmenion]

interestingly enough, you do not have to provide the modified sources openly to everyone, but only to your paying customers. so it would not be necessary to provide online download links. it would be quite sufficient to give private links to paying customers or provide the sources to them via physical media.

you can _not_, of course, limit these customers rights to again publish the same sources openly to the public on their own behalf.

[K0kt409P]

interestingly enough, you do not have to provide the modified sources openly to everyone, but only to your paying customers. so it would not be necessary to provide online download links. it would be quite sufficient to give private links to paying customers or provide the sources to them via physical media.

Unless the modified source code is distributed along side the binary, you must grant ALL requests for source access, not just from those who have received a copy of the binary from you.

Note also that the GPLv3 prohibits tivoization, i.e. any mechanism which is meant to prevent the user from replacing a stock binary with one of their own choosing. As a result, a commercial game built on OpenMW could not be released on a console.

[Chris]

Unless the modified source code is distributed along side the binary, you must grant ALL requests for source access, not just from those who have received a copy of the binary from you.

I don't believe that's true. You only need to provide sources to your licensees, no one else.
https://www.gnu.org/licenses/gpl-faq.ht ... emandACopy
"No. The GPL gives him permission to make and redistribute copies of the program if and when he chooses to do so. He also has the right not to redistribute the program, when that is what he chooses."
Note the use of the word 'when' in that second sentence. If I make a GPL program, and give a binary to Jane Doe, I only need to provide the source to her on request. If John Smith then comes along and asks for the program (source or binary) it is up to my discretion as to whether I give him a copy; I'm under no obligation to. If he got a copy from Jane Doe, then its between her and him, not me. I only need to give the source to people who licensed the program from me.

[K0kt409P]

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

My friend got a GPL-covered binary with an offer to supply source, and made a copy for me. Can I use the offer myself to obtain the source?

Yes, you can. The offer must be open to everyone who has a copy of the binary that it accompanies. This is why the GPL says your friend must give you a copy of the offer along with a copy of the binary—so you can take advantage of it.

So, unless the source code is distributed alongside the binary, you must grant anyone with a binary access to the source code, regardless of how the got the binary.

[Parmenion]

indeed. but the given example does not contradict what I said.

the binary might be sold. source has to be provided to anyone that bought the binary.

in the given example, the friend that bought the binary (and has the source) would not have been allowed to share the binary. thus there would be no need to accompany any binary with source code.

he would, on the other hand, be allowed to:
- give the source code to any other person
- build binaries from the source as well and give those away for free or sell those binaries for any price he wishes. in both cases he would have to pass on the sources alongside the [his!] binaries.

but the original person/company that sold the binary to your friend only needed to provide the sources to legal paying customers (your friend in this case). now this becomes quite theoretical/technical as we are living in a digital world where the original binary and the friends self-build custom-binary might (compiler-setting being equal and all) be bit-identical to the original binary. so the friend (buying customer of the original product [that has the sources legally at hand]) is not allowed to give away a copy of the original binary, but he is allowed to build a bitwise exactly identical version of said binary and give this artifact (of his own making) away. and he has to include the sources.

[K0kt409P]

indeed. but the given example does not contradict what I said.

the binary might be sold. source has to be provided to anyone that bought the binary.

in the given example, the friend that bought the binary (and has the source) would not have been allowed to share the binary. thus there would be no need to accompany any binary with source code.

The GPL does not allow you to prohibit your licensees from redistributing the program, in either object or source form.