OpenModelica

OpenModelica is an open-source environment for modeling and simulating complex systems using the Modelica language. It supports multi-domain simulations (mechanical, electrical, thermal, etc.) in an equation-based format. A graphical editor (OMEdit) eases model building, while advanced solvers handle large differential algebraic systems. OpenModelica suits academic research or industries wanting a free, Modelica-compliant tool to explore multi-domain system behaviors with equation-based modeling approaches.