Galactic Empires

Galactic Empires for Networks (Gen) is a Swiss Multiplayer Game (1984–2000) that is still playable today after more than 40 years. It was developed in several steps by three first-generation ETH computer science graduates: Peter Vrkljan, Jochen Walz, and Peter Leikauf. 

They wrote a network-capable real-time strategy game between 1984 and 2000, starting from a simple Apple II program.

Source: https://stage.chludens.ch/games/galactic-empires-for-networks-gen/