ScholOnto
Discord
ah, that is both informative and sad to hear. i think ahead of its time is a reasonable diagnosis.
ScholOnto I think was also ahead of its time: had a working prototype integration into a Word processor for directly authoring discourse-graph like things while drafting a manuscript (described here: https://onlinelibrary.wiley.com/doi/abs/10.1002/int.20188)
the idea DiscourseGraphs is rooted in a bunch of models like SEPIO (h/t <@602622661125996545>) and ScholOnto that have been around for various amounts of time, though not yet with (to my knowledge) serious widespread adoption.