DEVSimPy is a graphical environment in Python for modelling, simulating and analysing discrete event systems based on the DEVS formalism. You build models by dragging and connecting components on a canvas. Simulations can be started, paused and adjusted while a panel shows states and events. The software builds on the PyDEVS and PyPDEVS simulation engines, has a plugin system and can also run from the command line. Its audience is researchers, teachers, students and engineers. DEVSimPy is a desktop application that you install with pip or from the source code.
The project is developed by a researcher at the Université de Corse in France, within a CNRS research unit, and is published on GitHub under the GPL v3. The latest PyPI release seen, version 5.1.1, dates from April 2025, and the repository shows commits as recent as October 2026. The developers offer no cloud service: the software runs locally, so your models and simulation data stay on your own computer.