OpenModelica is described as '– A Free Modelica Environment!
OpenModelica is an open-source Modelica-based modeling and simulation environment intended for industrial and academic usage. Its long-term development is supported by a non-profit organization – the Open Source Modelica Consortium (OS' and is a circuit simulator in the education & reference category. There are more than 25 alternatives to OpenModelica for a variety of platforms, including Windows, Linux, Mac, Web-based and Python apps. The best OpenModelica alternative is MATLAB. It's not free, so if you're looking for a free alternative, you could try Spyder or SciPy. Other great apps like OpenModelica are Circuit JS, NumPy, LTspice and CircuitJS1 Desktop Mod.
Simulink Is an alternative to OpenModelica not the whole MATLAB