I used graphviz as the main visualisation for bear-note-graph [1], and it's super-easy to use programmmatically, and gives decent-looking results even for large graphs. It is also pretty customizable.

I have a WIP version now using D3, and that one has been harder to manage (when the graph is too large you don't want to have it animate the layout on the fly). If you are curious, I used the same D3 code I have in the WIP to present a sitemap of my blog [2]

    [1] https://github.com/rberenguel/bear-note-graph
    [2] https://mostlymaths.net/sitemap/

I've been pondering building a big interactive chart, like a decision tree or differential diagnosis chart, that maps goals/needs/problems to docs/examples/tools (for the Nix/NixOS/Nixpkgs ecosystem, but the basic concept applies to any sprawling ecosystem where discovery is hard).

I recently stumbled on https://github.com/mermaid-js/mermaid, which seems like it has an interaction model that could support what I have in mind (minus the question of whether there are performance cliffs that'd make it unsuitable).

If you considered mermaid while working on bear-note-graph, could you share the conclusions you came to?