Wikipedia
PowerDEVS
PowerDEVS [BK011] is a general purpose software tool for DEVS modeling and simulation oriented to the simulation of hybrid systems. The environment allows defining atomic DEVS models in C++ language that can be then graphically coupled in hierarchical block diagrams to create more complex systems.
It is developed at Universidad Nacional de Rosario ( Argentina) by Ernesto Kofman, Federico Bergero, Gustavo Migoni, Enrique Hansen, Joaquín Fernandez, Marcelo Lapadula and Esteban Pagliero.
The distribution is totally free.