Some special notes about the compiler for the creation of a parallel executable are important at this point. The compiler mpif90 is often a script/wrapper which calls the actual compiler with predefined compile/link options. The actual compiler depends on the MPI installation. If the MPI installation was done with e.g., the gfortran compiler, then mpif90 will use the gfortran compiler. But it is possible to use, for the compilation of the deMon source, a compiler which is different from the one used for the MPI installation. In this case the user has to take care about additional include paths, library paths and library names. An example of using the Intel compiler for the compilation of the deMon2k source code together with MPI libraries created with the gfortran compiler (from OpenMPI) is shown in the database file Linux-x86_64.mpi.mixed.