Hello, I have uploaded dependency diagrams for all boost libraries here: http://www.steveire.com/boost/deps-june-14/ The following incidental modules exist: incidentalModules["mpl"] = ("mpl", "type_traits", "typeof", "utility") incidentalModules["math"] = ("math", "lexical_cast") incidentalModules["spirit"] = ("spirit", "pool", "thread", "date_time", "serialization", "chrono", "interprocess") incidentalModules["graph"] = ("graph_", "disjoint_sets", "bimap", "property_map", "mpi", "graph_parallel") incidentalModules["scope_exit"] = ("scope_exit", "local_function") incidentalModules["range"] = ("range", "algorithm", "tr1", "random") The "incidental spirit" module and the "incidental range" modules are problematic. When the serialization->spirit range->algorithm edges are removed, they cease to exist as incidental modules, and the dependency graphs simplify: http://www.steveire.com/boost/after-edge-removal-june-14/ Compare: http://www.steveire.com/boost/deps-june-14/assign.png http://www.steveire.com/boost/after-edge-removal-june-14/assign.png http://www.steveire.com/boost/deps-june-14/range.png http://www.steveire.com/boost/after-edge-removal-june-14/range.png There are obviously more edges that can be investigated, but I recommend addressing serialization->spirit range->algorithm as a priority for now to remove those incidental modules. The "incidental mpl" module is not a priority problem, because anything which depends on the "incidental mpl" module mostly also depends on its dependencies. So, transitively speaking, it is mostly not a problem. It would be nice to resolve it a bit, but it does not need to be a priority. http://www.steveire.com/boost/deps-june-14/mpl.png The "incidental graph" module is not a priority problem because few other modules depend on any of it (only numeric_odeint). So, transitively speaking, it is mostly not a problem. It would still be nice to resolve it a bit to affect the modules inside the closure, but it does not need to be a priority. http://www.steveire.com/boost/graph-rdeps-june-14.png The "incidental scope_exit" module is being addressed afaiu, but it is also not a problem, transitively speaking. Nothing depends on either of them. Thanks, Steve.