The Planet Simulator is a Model of Intermediate Complexity (MIC); suitable for climate and paleo-climate simulations and time scales up to ten thousand years or more. It runs on a wide range of hardware and operating systems including massive parallel cluster and workstations with UNIX; Solaris; Linux; MAC OS or any other UNIX style operating system. The priorities in development are set to speed; easy handling and portability. Its modular structure allows a problem dependent configuration. A graphical Model Starter (MoSt) can be used to select a model configuration from the repository; set its parameters; compile and run the model. The model can be run either in production mode for maximum performance or in interactive mode using a Graphical User Interface (GUI). This GUI is both a real time visualization interface for all model variables and a tool for tuning and experimenting with the model.