Right now, Andy is perhaps the most sophisticated thinker in this space sharing his insights and prototypes (meta-knowledge work, backlinked evergreen notes, spaced repetition, new UX/UI for these systems, etc). Here's some additional pointers:

- Andy livestreamed a demo of him on a typical work session: https://www.youtube.com/watch?v=DGcs4tyey18

- this Patreon post explains in greater lenght his OS-level spaced repetition approach: https://www.patreon.com/posts/bringing-ideas-36925173

- Andy is working on a prototype of that system, called Orbit, which might be available soon: https://twitter.com/withorbit

- in regards to his specific writing/thinking system, here's a couple more clarifications: https://notes.andymatuschak.org/z4AX7pHAu5uUfmrq4K4zig9x8jmm... https://notes.andymatuschak.org/z6f6xgGG4NKjkA5NA1kDd46whJh2...

- Obsidian has a plug-in which replicates the sliding panes of Andy's notes: https://forum.obsidian.md/t/andy-matuschak-mode-v2-7-updated...

I think the space of graph/backlinked personal notes/knowledge systems is taking off [1], with many solutions free and open-source. (Of that list, many have spaced-repetition plug-ins not referenced there.) It will be interesting to how the field matures in a couple of years.

[1] https://www.notion.so/db13644f08144495ad9877f217a161a1?v=ff6...