I’m making a chess game in Unreal which will also feature single player mode using a chess engine. My first instinct was to use Stockfish but it is licensed under GPL. Unreal Engine EULA states:
This means, for example, that you may not combine the Licensed Technology with code or content that is licensed under any of the following licenses: GNU General Public License (GPL), Lesser GPL (LGPL) (unless you are merely dynamically linking a shared library), or Creative Commons Attribution-ShareAlike License.
So I guess that means I cannot use Stockfish. I searched for alternative chess engines but most of them are licensed under GPL too and the only ones compatible may be some pretty old if I recall correctly. That forces me to run the game engine on the server side which is pretty easy but costly!
Is there any chess engine I can use in my unreal project?