The ParMETIS library (in contrast to METIS) is distributed under a custom, non-free license and can thus not be shipped with BoSSS. Compiling/installing ParMETIS on a Linux machine is usually not a problem and thus not discussed here.
For Windows, you have to compile your version of ParMETIS yourself. You can obtain a copy of the source code [here](http://glaros.dtc.umn.edu/gkhome/metis/parmetis/download). BoSSS has been tested succesfully with ParMETIS 4.0.3, which is why recommend this version. The compilation process requires [CMAKE](https://cmake.org/) and some version of Visual Studio with a C++ compiler (any version, including the free community versions, should work). The compilation process is explained in detail [here](https://github.com/INMOST-DEV/INMOST/wiki/0204-Compilation-ParMETIS-Windows). In addition to the instructions given there, you should the boolean entry SHARED to the cmake configuration such that the corresponding Visual Studio solution is configured to create a shared dll instead of a lib file.
