GRAPH - simple graph data structure and algorithms

The GRAPH library strives for simplicity both in backing data
structures and in usage. Graphs and Digraphs are represented as CLOS
objects with methods and algorithms provided for graph manipulation
and analysis.

Note: currently this library is only supported on SBCL, Clozure CL,
      and Allegro CL because of the need to create hashes with custom
      equality tests, however custom equality tests are commonly
      supported so extending to other lisps should be simple. Patches
      welcome.

For more information see http://eschulte.github.com/graph.