This is the native MS windows release of OpenFOAM, an open source toolbox for Computational Fluid Dynamics (CFD). It was built with MinGW C++ as a set of native windows applications, which improves performance and eliminates the need for Unix emulations.
Of course the idea to port OpenFoam to Windows platforms is very reasonable. But it has to be done properly and, sorry, this is not the case. I tried to install the recommended OpenFoam-1.5.00b-wininst.exe package twice on two different Windows XP machines in various locations and always crashed with numerous messages such as "Error opening file for writing" in the \doc\Doxygen\html directory. I asked the initiator of the project for advice - no response so far.