Building computer models from small pieces

Computer models can be built by assembling code fragments. Here we describe the BehaviourComposer, which supports browsing for small modular program pieces called micro-behaviors and their assembly and execution. Using a web browser, the model builder finds and customizes micro-behaviors and associates them with prototypical agents. These micro-behaviors run as independent processes. Different combinations of micro-behaviors produce the desired behavior of each element of the model. One of the challenges is creating a runtime environment in which several un-ordered micro-behaviors can run together without conflict or the need to explicitly interface them. Another challenge is creating and organizing libraries of micro-behaviors.