As OGS-6 is a reimplementation of OGS-5 with new concepts and methodologies there will probably never be complete feature parity. We provide binaries of OpenGeoSys-5 ready for you to use. Support is limited but you may ask questions or report bugs via our discussion forum mailing list.
On Windows you may have to install the appropriate Visual Studio Redistributable:
You can get the latest OpenGeoSys-5 (with recent bug-fixes) version from our Jenkins CI system. Binaries for Windows (64-Bit) and Linux are provided for the OGS FEM-simulator under “Last successful Artifacts”.
Source code is hosted on GitHub: https://github.com/ufz/ogs5