I am still learning graphs, BGL 1.48.0 so beginner questions: 1. not sure what adjacency list/matrix are used for other than building a graph for traversal. Or maybe this is it? 2. I need to build a sparse network. So I am using adjacency_list_io.cpp by Francois Faure (2001). In this example I can read(g2), but when outputting std::cout << write(g2) I get lots of translation errors :-( I know I do not give details here but maybe someone could guess a -D??? to make adjacency_list_io.hpp happy. (The read(g2) works fine) Or I can certainly provide some of the error message. Also has Dr. Nick Edmonds completed (or near completion) of "active-message" based release (MPI)? Thank you. Andrew M. Neiderer US Army Research Laboratory