JModelica/JModelica

OpenModelica is an open-source Modelica-based modeling and simulation environment intended for industrial and academic usage.

a rust-native Modelica compiler for fast, composable, scientific computing

A Modelica to computer algebra system translator written in python.

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)

OpenMDAO repository.

Simulation framework for nonsmooth dynamical systems

Open Source Optimization of Dynamic Multidisciplinary Systems

Python modules for automating Modelica simulations and for running unit test for the Buildings library

Free (standard conforming) library to model mechanical (1D/3D), electrical (analog, digital, machines), magnetic, thermal, fluid, control systems and hierarchical state machines. Also numerical functions and functions for strings, files and streams are included.