I was playing with the code that used to live in contrib/callgraph - something I wrote when I was working on graph analytics stuff for Oracle Labs, and added d3-friendly output to it. Then ran across a library that does 3d visualization on top of that.
Here is a graph of package dependencies for the NetBeans source tree. I intentionally excluded a few classes from org.openide.util (Lookup, NbBundle, RequestProcessor), since pretty well everything depends on them: https://timboudreau.com/files/nb-packagegraph/ -Tim -- http://timboudreau.com
