Javasrc creates a set of HTML pages out of your Java source code. Here is some sample output. The format looks like javadoc, so you should find navigation very familiar. The methods and classes are cross-referenced, so you can easily navigate through the code by following the links. When you click on a definition of a class or method, you can see all the places in the code that reference that class or method.
Javasrc is written in 100% Java, so you should, in theory, be able to run it on any Java 1.2 or later platform. However, I have only tested the latest version on win32. (Earlier versions were also tested on Solaris). Javasrc uses the Java parser ANTLR. The core parsing code comes from an ANTLR example in an article written for the Java Developer's Connection: "Parsers, Part IV: A Java Cross-Reference Tool". You'll have to register with the JDC to read the article, but registration is free.
You can find the source code on SourceForge. You are free to improve upon it. If you decide to redistributed a derived work, please mention somewhere in your documentation where the original came from, just as I've given credit to ANTLR and the Java Cross-Reference Tool. If you'd like me to incorporate a change you've made into javasrc, you can contact me via the Javasrc discussion groups.
I took over Javasrc last year. It was originally written by Keith Johnson. Several other folks have contributed to it; here is a complete list of the contributors.
Thanks to SourceForge for hosting this project.