Several programming environments are currently available for the design and simulation of Modelica models. Certain environments also have facilities for post-processing results of simulations, 3D visualization of mechanical systems simulation, CAD integration, special support for real-time and hardware-in-the-loop simulation, and support for integrated modeling, simulation, post processing, and documentation. The first full Modelica environment to appear was Dymola, soon followed by MathModelica, renamed in 2012 to Wolfram SystemModeler.The OpenModelica environment was the first open source Modelica environment. Its development started in 1997 resulting in the release of a flattening front end for a core subset of Modelica 1.0 in 1998. After a pause of four years, the open source development resumed in 2002. The Open Source Modelica Consortium, which supports the long-term development of OpenModelica, was created in 2007, initially with seven founding organizations. The scope and intensity of the open source development has gradually increased. A the time of this writing, the consortium has forty-five supporting organizational members. Principles of Object Oriented Modeling and Simulation with Modelica 3.3: A Cyber-Physical Approach. Peter Fritzson.