Very interesting. I always thought of knowledge as a graph (as opposed to a document or a tree), and browsing the graph of knowledge will be really useful for learners.

I think the obstacle is more on the authoring side (how to build/edit graphs as easily as plain documents). There is also standard taxonomy challenges, about choosing the "types" of the nodes and the associations (values of the `instance_of` of the `Association`s in TopicDB). If the platform restricts things to a fixed taxonomy, you lose expressiveness, but on the other hand if you let users create any-which category they want things can grow quickly out of hand).

A related project in that space is https://metacademy.org/ whose code is here https://github.com/metacademy/metacademy-application

I was working on an app similar to contextualize a while back, but had to pause because of other projects, but I hope to come back to it soon. I hand't gotten very far on it, so maybe I can contribute to contextualize. My main focus is on building tools for serialization/deserialization of the graph data to a text-based format that can be stored in git repos so that multiple authors can collaborate on building out a knowledge base using pull requests, see data fixtures here https://github.com/minireference/structure-api/tree/master/d... )