Modelon Open Source Resources

To support the system simulation community, Modelon has developed open-source tools and resources that are available to everyone. Learn about them below.   

Open-source tools and resources


JModelica is an open-source Modelica compiler.

Modelon is making the following changes to Assimulo, PyFMI and FMI Library are being moved to github. All other parts of the platform, including the Modelica compiler and optimization capabilities, are discontinued as publicly available open source.

The platform is under active development and continues to be available for academic and commercial use.


PyFMI is a package for loading and interacting with Functional Mock-Up Units (FMUs) both for Model Exchange and Co-Simulation, which are compiled dynamic models compliant with the Functional Mock-Up Interface (FMI).

FMI is a standard that enables tool independent exchange of dynamic models on binary format. Several industrial simulation platforms support the export of FMUs, including, Dymola,, OpenModelica and SimulationX, see here for a complete list. PyFMI offers a Python interface for interacting with FMUs and enables for example loading of FMU models, setting of model parameters and evaluation of model equations.

PyFMI is available as a stand-alone package or as part of the distribution. Using PyFMI together with the Python simulation package Assimulo adds industrial grade simulation capabilities of FMUs to Python.

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