The OpenFOAM source code is available at https://sourceforge.net/projects/openfoam/files/v1906/OpenFOAM-v1906.tgz https://sourceforge.net/projects/openfoam/files/v1906/ThirdParty-v1906.tgz
The HowTo instructions to build the code is https://www.openfoam.com/download/install-source.php
There is no point in loading in this area the packages, the above pointers privide the info requierd to access, download and compile the code.
The two examples listed in this area are provided as examples of the most used algoriths used by selecetd dataset of openFOAM, the matrix multyply and the sparse matrix/vector multiply