I would like to thank the Boost Graph implementers (and the general Boost community) for coming up with a great set of patterns for dealing with graphs. I have started something similar for Scheme (a Lisp dialect), and would like to acknowledge where the great ideas came from. Keep up the good work! Jonah http://www.nongnu.org/rgraph/ README excerpt: Rooster Graph is a graph library for Scheme. Patterned after the popular Boost Graph Library for C++, it allows for a very clean separation between the graph container and graph algorithms. It does not have the complete functionality of the Boost Graph Library, but it does go a bit further by having both strict- and lazy-evaluated methods; the user of the graph has pause/continue/stop control and is not constrained by memory. Rooster Graph uses Scheme macros to get the benefit of speed while having generic operations. It has only been implemented on CHICKEN Scheme, although porting it to other Scheme implementations would be quite easy.