Freeciv

Freeciv is a multiplayer turn-based strategy computer game based on the Sid Meyer Civilization series (closest to Civilization II). It was created by an independent team of developers, and is distributed under the GNU General Public License. The source code is available on the game's website.

At the beginning of the game, each participant becomes the head of a primitive tribe in 4000 B.C. and leads their people for centuries. The game is based on building cities, in which, in turn, the population grows, sciences are learned, and taxes are collected. In the cities, for their further development, it is necessary to build various buildings and structures, and around them - to carry out land reclamation, build mines, roads and other infrastructure elements. Also, military units are created in cities, serving to defend against aggressors and wage offensive wars.