(10-06-2018, 10:02 AM)Antibody Wrote: There's also no mention of licensing requirements: all content must be made available under copyleft licensing (specific details vary, but GPLv3 is always fine).
Don't forget the “or later”, that's because people did not forget it at GPLv2 time we can now ask for GPLv3 today.
(10-08-2018, 05:04 AM)Lyberta Wrote: I suggest to dual license with CC BY-SA 4.0 too.
Yes, and by the way CC BY-SA 4.0 is known to be one-way GPLv3 compatible (from CC to GPL):
By the way to avoid people having headaches by reading kilometers of boring legalcode each time they want to check for the legal status of a random given file, dual licensing make things explicit for anyone.
So the safest option would be to dual license assets with both “
GPLv3 or later and CC BY-SA 4.0 or later”.
Note that CC BY and CC BY-SA ar “or later” by default for derivative work since CC 2.0:
- 1.0 “You may distribute, publicly display, publicly perform, or publicly digitally perform a Derivative Work only under the terms of this License”
- 2.0 “You may distribute, publicly display, publicly perform, or publicly digitally perform a Derivative Work only under the terms of this License, a later version of this License with the same License Elements as this License, or a Creative Commons iCommons license that contains the same License Elements as this License (e.g. Attribution-ShareAlike 2.0 Japan)”
- 2.5 “You may distribute, publicly display, publicly perform, or publicly digitally perform a Derivative Work only under the terms of this License, a later version of this License with the same License Elements as this License, or a Creative Commons iCommons license that contains the same License Elements as this License (e.g. Attribution-ShareAlike 2.5 Japan)”
- 3.0 “You may Distribute or Publicly Perform an Adaptation only under the terms of: (i) this License; (ii) a later version of this License with the same License Elements as this License; (iii) a Creative Commons jurisdiction license (either this or a later license version) that contains the same License Elements as this License (e.g., Attribution-ShareAlike 3.0 US)); (iv) a Creative Commons Compatible License”
- 4.0 “Section 3 – License Conditions. b. ShareAlike. In addition to the conditions in Section 3(a), if You Share Adapted Material You produce, the following conditions also apply. The Adapter’s License You apply must be a Creative Commons license with the same License Elements, this version or later, or a BY-SA Compatible License”
That's why I sometime distribute my work under “cc by 4
and before”
Notice the “derivative work”, the wording always talk about other possible licenses when derivated. For raw copies, if we use CC BY-SA 4.0 as an example we can read:
- 4.0 “If You Share the Licensed Material […], You must: retain the following if it is supplied by the Licensor with the Licensed Material: […] a notice that refers to this Public License”
So you can distribute a game under CC By SA 4.0 even if some assets uses 3.0 (the whole being a derivation of the part) but it looks like it's hard to flip a lone file from 3.0 to 4.0. So, saying “or a later version” for CC is not a bad idea by itself, even with the explicit “or later” clause because this clause is written when talking about derivatives.
This comment is licensed under cc by 4 and antecedent.