OpenFOAM®1 is a versatile multi-physics, open source2, simulation toolbox produced by OpenCFD. OpenFOAM is renowned for its wide support of numerous Computational Fluid Dynamics (CFD) methods.
Symscape has developed a custom version of OpenFOAM that provides solvers and utilities that run as native command-line applications under Windows. These source code modifications are freely available in accordance with the GPL. This same custom version of OpenFOAM is used by our Caedium RANS Flow add-on.
You'll find an active developer and user community for OpenFOAM on the CFD Online OpenFOAM Forum.