@Lee
Just would like to add, if GameGuru would be free and open-source you could request free hosting from GitHub. Of course not every one get it, but GitHib is willing to "support" free and open-source projects by hosting them for free.
To limit access to GG users, is an interesting idea. It would mean you are not only expect people to contribute for free but also you want them to pay so they can contribute
I understand paid developers going to work on GG but the whole point to make something open is to be open to free contribution, and I thought this is what TGC trying to do here. If you even put a gateway on GitHub and only GG owners can access the source, free contribution will be out of question totally and paid developers going to contribute only as long they get paid. Stab in the Dark who is working on the new physics system did actually state that last year his got the system ready but not willing to give it to you for free but now he is working on it probably because he get paid but not otherwise......
In my opinion the best would be if GG would have two versions:
GameGuru Community Edition
-free and open-source for any purposes to anyone
-shared on github
-include no assets
-maintained by TGC (compiled, released new version every 3-6-12 months)
-developed by the community!!
GameGuru TGC Edition
-based on GG CE
-require a one time fee (purchase on steam as it is now)
-only GG owners and/or selected contributors have access to it source code (apply gateway on this version)
-include tons of free assets
-maintained and developed by TGC
-include features developed by paid developers!!
So...
GG Community Edition can receive free contribution, it would be developed ONLY by the community if TGC add any feature it considered a gift. This way, it may even qualify for free hosting on GitHub and to support it development TGC accept contribution, donation and purchase of GG TGC Edition.
GG TGC Edition would take the role of the current GG version and built on top of the community version and this way take advantage of any free contributions but only this version would include features developed by paid developers and the free assets.
In my opinion TGC have nothing to lose with my idea, if the new phyiscs system make it in to GameGuru and going to be that awesome as it looks like, the phyiscs and free assets on it own going to worth to buy GG TGC Edition for anyone while you can keep the gate open for free community contribution at the same time with a free and open-source version.
But considering GameGuru don't even have a demo version, maybe to have a free and open-source version is totally out of question or scary.
Anyway, I wish the best.