"20 year old code"?!? I have been using graphviz since early '90s, when ek provided a first prototype. You mention a possible improvement of classes of nodes/e

"20 year old code"?!? I have been using graphviz since early '90s, when ek provided a first prototype. You mention a possible improvement of classes of nodes/edges. If I understood correctly, this is typically used for styling, and is most commonly achieved via a pre-processing step. We all use our own tools for that (I've personally used m4, cpp, sed, Tcl, and I'm sure others that I forget). Graphviz is one of the tools that I use in a wide variety of circumstances. I'd say the most satisfying cases from all these years were (a) producing a genealogical graph of around 1000 people drawn with neato (very organic-looking!); and (b) producing orgcharts for an organization (that had to look acceptable to what people were used to seeing). Many thanks for your work all this time!