There a bunch of other Boost.Graph files that include things from boost/graph/parallel which uses Boost.MPI. This was done to allow more transparent use of parallel graph data structures and algorithms, just by including <boost/graph/use_mpi.hpp>.
Where is this documented? * On a related note: the parallel graph lib does not appear in the library list at http://www.boost.org/doc/libs/1_41_0. * libs/graph-parallel/index.html is broken (points to the wrong location). * I'm having trouble understanding how the infrastructure of the library works from browsing the docs... can't find any mention of boost/graph/use_mpi.hpp, or even any complete examples for that matter. IMO it's desirable to break this dependency if possible, but I can't make any suggestions without understanding what's going on ;-) Cheers, John.