I've exchanged more email with Bruce. If anybody wants to see the full back-and-forth, let me know, but basically he neatly closed all loopholes for code- it must be GPL, or a license that is compatible.
But the content... that's another story. The key line from his side of the dialogue is in bold italics.
Bruce:
Thanks very much, for spending the time on the detailed replies. We're really in very novel ground here, I really appreciate this.
Basically, the issue hasn't been hostility to making a profitable project, period, the only question has been to what extent the author becomes a rights-holder under the GPL (and, of course, transfers those rights to others). I'm certainly not trying to screw over our coders- if anything, my desire would be to become profitable, and then hire coders to contribute to the GPL source (not a fork, mind you!) which would both enhance my game and provide more value-added down the road for future projects. Much hinges upon whether or not I can legally sell the game at all, basically. This could be a new model of game development. My questions are mainly in response to the (few, and not engine contributors) people who have said that the GPL basically puts all work in a game into GPL. If the answer to that is, "no", then the question becomes one of whether or not those non-derivative assets have enough value in and of themselves to make a profitable product a reality.
I think in this case the content is interpretive code. The issue is whether that content is derivative of the GPL component, or is only "input" to the GPL component. And this is still up in the air.
That's the key right there. We're not talking about "prior art" in some sense, or work that exists only with the software's direct interaction. We're talking about non-proprietary data. Bitmaps, 3D meshes, sound files, and music. None of them was made using this software, all of them can be used outside the software, even "correctly" used, in the conventional sense.
So, yes, I would have to conclude that they constitute "input", and are merely data- data that I can license seperately of the engine and my own code (which, as you've already confirmed, would be GPL).
At any rate, I think that's a safe enough position to move foward and sell the game, when it's complete enough to sell.
The coders will be satisfied, I think, because I've just created a potential marketing avenue. They'd merely have to find people to make content that they could license, and partner with them to make products. And nobody will be able to complain about people acting as "technology vampires", because we're all contributing to the pool collectively.
I don't think anybody will want to sue me, under those terms. It's a win-win- if I innovate, everybody can have that innovation, if I create content, it adds value to my project. If anything, they'll be quite happy that we've reached a situation that creates a workable compromise where everybody can make money while feeling virtuous.
If you see a huge hole in that, or wish to talk to the Spring Engine's core developers about it, then please feel free to let me know, or simply drop in at our website, spring.clan-sy.com. You certainly don't have to assume that I'm saying the truth when I say that this probably will make the vast majority of us quite happy, but I can assure you that it probably will.
Thanks very much,
Greg Wolfe
Anybody see any massive holes in the logic laid out below? Anybody want to sue me, etc.?
Or are we all reasonably satisfied, and I can proceed, so long as my code (including CEG) is GPL?
So far as I can see, that removed the legal impediments to making games we can sell, to finding foundation grants, to finding venture capital... etc. I think this represents a massive win-win for everybody. Does anybody have further objections?