Ok, quick recap:
The issues with permissive licensing (BSD/MIT/ZLIB) is apparently:
1 ) Making it permissive may cause SEGA's to ask for cease and desist
Ok, I understand where you're coming from, but this is just the engine, there's nothing in the code or math that belongs to or is related to SEGA or SEGA's trademarks:
Physics engine? - No, they don't even use a decent sonic physics system in their engines anymore, barely in 2D, forget 3D.
Graphics system? No, making your own original rendering system isn't something that you can legally penalize anyone for. SEGA does not own OpenGL, Gen's code, or the algorithms he's using.
The engine has nothing to do with SEGA, just the engine alone would basically be this:
2) Permissive licenses means that people wouldn't share code
Well, are you speaking from what you've seen happen with other projects? Because I've seen that even with ZLIB/MIT/BSD licensed projects, many people will post what they're working on, get feedback, and many times release source code or parts of it.
I would say that there would be no difference in people sharing code if a permissive or "un-permissive" license is used, the benefit of a permissive license is just that - the code has no restrictions
Also, I know there's at least 2 game related projects that start the out with LGPL and later go to a permissive license.
SDL 1.2 LGPL -> SDL 2.0(and possibly 1.3) ZLIB: http://www.libsdl.org/license.php
Ogre 1.7 LGPL -> Ogre 1.8 MIT http://www.ogre3d.org/licensing
If a new, general use game engine is going to developed, I still don't see any real drawbacks to use a permissive license, that's just my opinion.
This post has been edited by James K: 10 March 2012 - 08:58 PM