0 A.D.

UNRELEASED GAME – AVAILABLE This game is still in active development and available to the public for purchase in it's unfinished state, either in Early-Alpha or Beta (or any status in between). 0 A.D. features the real-time strategy gameplay components of building a base, training an army, combat, and technology research. The game is about economic development and warfare. The game will include multiple units and buildings specific to each civilization as well as both land and naval units.Source: Wikipedia, "0 A.D. (video game)", available under the CC-BY-SA License.