[amatic]

Is there a graphical interface, like Simulink, for Modelica?

[ptrott2017]

There are commercial ones like ones like Altair SolidThinking, Wolfram System Modeller, ESI's SimulationX and there are open source ones such as OMedit. Which meets your needs will be partly budget / workflow / toolbox support based. If your new to Modelica - then OpenModelica and OMEdit (OMEdit comes as part of the OpenModelica download) are great starting points. To get an idea of the available commercial and open source options see:

https://www.modelica.org/tools

and https://openmodelica.org/openmodelicaworld/tools

[choeger]

Many. Dymola is probably the go-to solution, but also openmodelica, simulationX and wolfram, I think.

Here is a list: https://www.modelica.org/tools

[vsskanth]

OpenModelica is free. There are many commercial IDEs like Dymola from Dassault, Wolfram System Modeler etc.