Rift SDK and GPL

From what I understand, the SDK is not compatible with GPL. However, I believe LGPL should be OK.

The problem is, the license can not be changed.
The only solution is to implement a GPL compatible SDK from scratch.
Thanks for the reply.

That raises a good point. Linking the oculus sdk with the released source code for any of the Quake or Doom series would be a gpl violation.
(Not that I wanted to, I avoid touching GPL code, but I'm sure some people might want to try)

Other games that are open source but incompatible due to gpl:
- flightgear
- oolite
- arx fatalis
- duke nukem 3d
- penumbra overture
- jedi outcast
- jedi academy
plus more.
(many more, but I only listed the ones that I thought would be good in vr)

Until making this list I didn't know arx fatalis had it's source released 2 years ago. It's one of the best first person rpgs, a spiritual successor to the Ultima Underworld series. It also uses a magic system where you write runes in the air with your hand, that would be awesome with a rift and a wiimote!

Oh my, this is really bad.

Someone needs to create a driver/sdk that's open source.

I wounder if some parts of the SDK are binary only. For example, is the interface code for the tracker open or will it have to be reverse engineered? Maybe the sdk fiddles with it's firmware, that might be a problem.

Then again, this could be a good way to make games companies do open source releases under a good license like MIT, BSD, ZLIB, LGPL etc. Too many of them use GPL, then we are blocked from adding support for things like havok animation, physx particles, fmod 3d geometry audio occulsion, oculus rift sdk, or any other "free but closed source" or gpl incompatible licensed components.

I wounder if some parts of the SDK are binary only. For example, is the interface code for the tracker open or will it have to be reverse engineered? Maybe the sdk fiddles with it's firmware, that might be a problem.

There's no binary parts, it's all open source.

Another option would be to create a LGPLv3 licensed proxy library that could be used in the GPL game.
Would that be a legal option ?

What's pretty annoying is when people fixate on the letter of the law rather than the spirit (of course, the letter isn't perfectly defined anyway). The Rift SDK source is open with only minor restrictions on it's use and distribution, and I have a hard time seeing how using it with GPL'd software would really restrict the latter's software. Is it really any worse than the closed-source "blob modules" such as nVidia and and ATI GPU drivers under linux? GPL is mainly established to prevent people from profiteering from free software by incorporating or interfacing with it in their own closed proprietary software. The Rift SDK does not do this.

With GPL, there's not even a clear-cut line when it comes to libraries. My understanding is that a closed application should not be able to rely on, or make calls to a GPL'd library. But what about the other way around, as would sort of be the case with the Rift SDK? The application is making the call to the Rift library, so the application relies on it, rather than the other way around. I don't think this violates the GPL

Regardless, considering that the GPL is constantly being violated and in much worse ways, if there actually is one due to interfacing with the Rift SDK, I think only the most insufferable of GPL supporters would raise a stink.

"msat" wrote:
What's pretty annoying is when people fixate on the letter of the law rather than the spirit ...

I hope you understand that not everyone is satisfied to operate without legal security.
I do not think it is unreasonable to ask for clarifications.

"msat" wrote:
Regardless, considering that the GPL is constantly being violated and in much worse ways, if there actually is one due to interfacing with the Rift SDK, I think only the most insufferable of GPL supporters would raise a stink.

Saying that it's ok to break a copyright license because other people are doing it already isn't exactly the smartest legal strategy.

"msat" wrote:
The application is making the call to the Rift library, so the application relies on it, rather than the other way around. I don't think this violates the GPL

The official GPL faq disagrees with you:

If you want your program to link against a library not covered by the system library exception, you need to provide permission to do that. Below are two example license notices that you can use to do that; one for GPLv3, and the other for GPLv2. In either case, you should put this text in each file to which you are granting this permission.

Only the copyright holders for the program can legally release their software under these terms. If you wrote the whole program yourself, then assuming your employer or school does not claim the copyright, you are the copyright holder—so you can authorize the exception. But if you want to use parts of other GPL-covered programs by other authors in your code, you cannot authorize the exception for them. You have to get the approval of the copyright holders of those programs.

So you can link Doom 3 with the rift sdk only if you can modify the version of the GPL license Doom 3 was released under. But only id software can do that. Same for all the other GPL games around, only their authors can add a rift sdk exception.

"kojack" wrote:
So you can link Doom 3 with the rift sdk only if you can modify the version of the GPL license Doom 3 was released under. But only id software can do that. Same for all the other GPL games around, only their authors can add a rift sdk exception.

As I understand it this is even more problematic for GPL software that has had a community of developers working on it. No one entity/person can add an exception, you need the agreement of every developer who has contributed code to the project because all developers retain the copyright to code they contributed.