In this report we give a full description of sim, a C++ library for discrete event simulation. The sim library supports both an event and process-oriented approach to developing simulations. Events as well as entities (which may be considered as events with states signifying episodes in its life-time) are provided as abstract classes that must be refined by the application programmer to define the actual events and entities participating in the simulation.

The sim library is integrated with the hush library, thus offering powerful graphic and animation facilities. However, the sim library may also be used independently, on both Unix and MS-Dos platforms.

This report presents an overview of the classes constituting the sim library (including the classes event, entity, generator, resource, queue, histogram and analysis) as well as two standard examples illustrating the deployment of the classes in writing simulation programs. Also, an example is given of how to create a graphical animation of a particular simulation. The appendix contains, moreover, a more extensive example of a jobshop simulation illustrating how the analysis class may be used to obtain measurements of complex queing behavior.

Keywords: discrete event simulation, events, entities, modeling, simulation experiments, simulation animation, simulation analysis