Hi all, I have a question regarding boost MPI and thread support. boost::mpi::environment uses MPI::Init to initialize MPI. I would like to be able to assess the supported thread level using MPI::Init_thread. Is it possible to first initialize MPI via MPI::Init_thread and then create a boost::mpi::environment ? the documentation reads: If the MPI environment has not already been initialized, initializes MPI with a call to MPI_Init does that also work if the initialisation is not carried out via boost::mpi::environment? Assuming the underlying MPI implementation supports it, is it safe to mix boost threads with boost MPI, at least at a FUNNELED level, carrying out all the MPI communications in the main thread? thanks for your help, Clément Rezvoy.