ViZDoom in josephmisiti/awesome-machine-learning, leomaurodesenv/game-datasets
Reinforcement Learning environments based on the 1993 game Doom 
created at June 26, 2015, 6:38 p.m.
C++
MAgent2 in krzjoa/awesome-python-data-science
An engine for high performance multi-agent environments with very large numbers of agents, along with a set of reference environments
created at Sept. 5, 2022, 4:29 p.m.
C++