Open Source Charting & Reporting Tools in Java

JGraphT is a free Java graph library that provides mathematical graph-theory objects and algorithms. JGraphT supports various types of graphs including: * directed and undirected graphs. * graphs with weighted / unweighted / labeled or any user-defined edges. * various edge multiplicity options, including: simple-graphs, multigraphs, pseudographs. * unmodifiable graphs - allow modules to provide \"read-only\" access to internal graphs. * listenable graphs - allow external listeners to track modification events. * subgraphs graphs that are auto-updating subgraph views on other graphs. * graph visualization using the JGraph library Although powerful, JGraphT is designed to be simple and type-safe (via Java 5 generics). For example, graph vertices can be of any objects. You can create graphs based on: Strings, URLs, XML documents, etc; you can even create graphs of graphs!