Zero-K

Zero-K is a free, open source, multiplatform, 3D and currently in continuous development RTS.

It's built on the Spring engine and carries many improvements and properties common to Spring engine games. These include; a couple competent AI, lots of lobby/hostbot/game-setting combinations, several thousand maps of up to 200 mb each, deformable terrain, scenarios and a scenario maker, Lua based interface and scripting, hundreds of Lua interface widgets and helper AI, up to 64 players per game, thousands of units in a game, the ability to zoom out and see all units in icon view, physics for both unit movement and projectiles, units can be under, in and on water, the ability to control any unit in fps mode, dead units leave wrecks that can be reclaimed for resources. Spring's favorite setting of a futuristic war involving waves of tanks with plasma cannons, tank sized robots with lasers, nearly indestructible super-capital ships, everything being made of metal and energy and nuclear mines is also something that ZK inherits.

Zero-K has a persistent Rpg element in the form of points for every multiplayer victory that can be spent on buying specialized units and upgrades for the starting commander unit. ZK also has an MMO like element called Planet Wars where players join clans and then try to take over a galaxy of planets by winning games on maps representing those planets to get gold influence and technology for specialized units. PW is intended to bring some context to games of ZK.

Unlike its Spring brethren, in ZK energy can only be converted to metal by improving existent metal extractors thereby preventing the turtling strategy. Currently the game has only one race and a flat tech tree. This removes the tech tier/ages common to spring games.