 Functionality such as zooming, rotation, playing and pausing simulations, setting colors and viewing cross sections is available through the player, with a sample screenshot shown below.Extending the back end is possible through an XML-based domain-specific language Biologo, which after lexical analysis and generation transparently converts to C++ extensions which can be compiled and dynamically loaded at runtime.The back end uses object-oriented design patterns which contribute to extensibility, reducing coupling between independently operating modules.