Zero-K is a free multi-platform open source real-time strategy video game.

Among the games powered by the Spring Engine, Zero-K makes extensive use of Lua scripting for interface and gameplay changes/enhancements,[1] as well as unique real-time strategy concepts such as a flat technology tree.

[3] The economy in Zero-K, consists of two resources, Metal and Energy which are used to create and repair buildings and units.

Depending on the player's performance, each mission yields a different number of experience points.

Planet Wars resets each time one clan achieves one or more of the three victory conditions - Conquest, Economy, Technology.

In a game of Chickens, the goal is to survive an onslaught of various semi-sentient alien creatures until their "Queen" attacks.