

Graphviz would have been my first suggestion. What other types of outputs are you looking for?
My second thought would be some sort of database software. LibreOffice has a MS Access equivalent (Base) where you could keep a table for each type of data, then express relationships. If you’re already comfortable with SQL it might work well, but otherwise might be overkill (though you could get just about any output you’d like from it).
































Awesome!
For what it’s worth, I got “fancy” with graphviz a while ago. One of the things it can output is SVGs, which can be used in a web browser for interactivity. For example, I set up one graph to highlight all the branches that are connected to a selected node, and I put links to navigate between different graphs. So there’s quite a bit possible there.