OpenFOAM the most comprehensive free CFD program that is currently available.
It has all the features that are necessary for a successful application of computational fluid dynamics. On top of that the source code is completely open and it is entirely free of charge. In conjunction with the good parallel scalability, this opens up great potential for increasing productivity and design safety with simultaneous cost reduction.
The focus of OpenFOAM is on computational fluid dynamics. But through the open and modular architecture, the software is also ideal for solving other tasks, such as calculation of electric and magnetic fields. In particular, highly customized solutions can be developed excellently by the limitless customization possibilities of an open source software.