Hi, The API for OpenMPI has changed at version 1.8.1 (in that many parameters have been made const). This breaks compatibility with MPE when using GCC (though Intel reports these as warnings, rather than errors). Attached is a patch to make MPE2 compliant with the current MPI3.0 specification (and therefore build correctly with OpenMPI 1.8.1). Apply in mpe2-1.3.0 directory: ~/mpe2-1.3.0$ patch -p1 < ompi-1.8.1.patch Thanks, Steven -- Steven Wright CS202 High Performance and Scientific Computing Performance Computing and Visualisation Department of Computer Science University of Warwick Tel: +44 (0)24 7657 3775