libgraph-perl - 1:0.9716-2 main

This module contains the Graph module for Perl, a framework for
creating abstract data structures called graphs and hypergraphs.
(It is not for drawing any sort of graphics; for that, see the
GD:: or Graphics:: set of modules.) It also contains implementations
of several well-known algorithms that operate on graphs, such as
finding transitive closures, strongly connected components
(SCCs) and articulation points.