https://github.com/eschulte/graph.git
git clone 'https://github.com/eschulte/graph.git'
(ql:quickload :graph)
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 and Clozure 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.