Open source RTS game built on top of the Spring RTS Engine

https://www.beyondallreason.info/download

You will need a lobby for the Spring Engine, such as SpringLobby. Once this is set up, go to your Spring data folder, and check out a copy of the game

git clone https://github.com/beyond-all-reason/Beyond-All-Reason.git bar.sdd

The game will now show in lobbies as Beyond All Reason $VERSION