Since I am no expert in programming nor FG I warn you that I might write a big nonsense here
Anyway, I fail to see any difference in what bomber requests and Israel's ideas *shrug*
I see three different license "domains": The core domain, the add-on domain and the content domain (aircraft and scenery I guess).
If you want to be able to allow different licenses to the different domains, then all you would need to do is define the interfaces between them accordingly (at arm length).
Now, do I understand correctly (or not) that bomber would prefer a CC license for the core and Israel a GPL? Is that the core difference in stand points here or am I missing something?
Because if you build an architecture so that the core treats add-ons and content as external modules to be executed (add-ons) / loaded (content), and not as linked libraries (be it dynamical or static) I believe you can freely choose one out of CC/GPL/commercial for any of the domains, no?!?
My understanding at the moment is that you guys would need to agree on the license of the core (CC/GPL) because I feel that you both agree that any module in the add-on domain or the content domain should be allowed to have a different license per module as the creator of the module wishes.
What would be downloadable from the web page of this project would probably be 100% free of proprietary and commercial modules and would still offer a full blast of core features, basic add-ons, as-good-as-possible world scenery and a decent amount of good aircraft.
Then all you need to do is define interfaces so that creators of additional modules can offer a download so that installation for the user is super-simple. In that way commercial people could e.g. create (or even port from another simulation!!) ultra-professional aircrafts, all they need to do is adapt to your hopefully easy to use interface.
But also developers can create GPL or CC aircrafts.
It would be a mixture of everything, but only in the add-on and content domains.
Let the most successful win in those two domains (of course we all hope that it will be the free versions
) while keeping the core CC/GPL, what ever you will decide on.
Again: If I just talked total crap due to not understanding things correctly, please just ignore.....or have the courtesy to tell me so that I can delete and not embarrass myself too much