Scalatron is a programming game in which bots written in Scala compete in a virtual arena for energy and survival.
Scalatron was released as free open-source software in 2012.
Bots are written in Scala, compiled into Java byte-code and executed by the server. The goal of each bot is to accumulate as many energy points as possible. Bot control functions are implemented as mappings from an input string, which includes a partial view of the arena, to an output string containing one or more commands.
The arena is a toroidal (i.e., apparently infinite) 2D cell grid. Each cell may be occupied by at most one entity. Entities include the players' bots; their spawned child bots; good (edible) plants and beasts; bad (harmful) plants and beasts; and walls. Consumed or otherwise damaged plants and beasts immediately re-spawn elsewhere in the arena.
Bots' primary commands are Move, Spawn (creates a child bot), Explode (damages surrounding enemy bots) and Set (persists some state information). A range of debugging commands are also available, including Log, Status, Say, DrawLine and MarkCell.