python, see https://www.python.org/
PyQt5, see https://www.riverbankcomputing.com/software/pyqt/
python-chess by Niklas Fiekas, see https://github.com/niklasf/python-chess
eco files by Niklas Fiekas, see https://github.com/niklasf/eco
content of training/matein from ScidVsPC, see http://scidvspc.sourceforge.net
content of training/tactics from scid, see http://scid.sourceforge.net
chess pieces by Colin M.L. Burnett, see https://en.wikipedia.org/wiki/User:Cburnett
leipfont.ttf by Armando Hernandez Marroquin, see https://www.chessvariants.com/who/ArmandoMarroquin
