The Behavior Language is a rule-based real-time parallel robot programming language originally based on ideas from Brooks 86, Connell 89, and Maes 89. It compiles into a modified and extended version of the subsumption architecture Brooks 86 and thus has backends for a number of processors including the Motorola 68000 and 68HC11, the Hitachi 6301, and Common Lisp. Behaviors are groups of rules which are activatable by a number of different schemes. There are no shared data structures across behaviors, but instead all communication is by explicit message passing. All rules are assumed to run in parallel and asynchronously. It includes the earlier notions of inhibition and suppression, along with a number of mechanisms for spreading of activation. (Author) (KR)