I am still testing how well web-based solutions work with JDex, to make me independent from any given machine I happen to be sitting in front of. You may have seen my other posts about Workflowy and self-hosted Obsidian. “Outline” is a new one I am working with at the moment. Ironically, Outline is not an outliner (but Workflowy is!).
Outline is very similar to OneNote or Obsidian because it is document-centric and allows the files to be nested and put into separate collections. As an editor, it is very elegant and allows for immediate editing and automatic saving. It allows multiple users to work at the same time, and to selectively share material with non-users. (GitHub)
Setting it up on my home server as a Docker container was easy once I understood how to create a login. Literally just two files: docker-compose.yml and .env that I can share if there is interest.
I already like it a lot and I am planning to move some areas or projects to Outline from my Workflowy that I have been using for 13+ years.
(Disclaimer: I am not involved with the provider in any way other than being an enthusiastic user, happy to help others.)