Ask HN: What are new Tools to help create online course?

I have been looking at newer tools that people have posted in Hacker news to use them in creation of online courses. I hope to create an online course in Music using these newer tools. More than that I think it would be good to get a listing of tools out that have potentials to used for online courses.

Just to name a few that I have seen: Barbra -- https://barbra.io/ -- to share notes among class takers. Edanswers -- says mainly for learning plans. Don't know how to use it yet. Intention -- https://about.i.ntention.app/ -- good tool to setup goals and stay motivated. Don 't know if the goals can be shared among users.

My idea so far is to have the whole course laid out as a mindmap (haven't found a tool yet), then linked to goals through Intentions with notes in Barbra.

Looking for suggestions on tools and systems that I could use. Note: I could use a big system like openedx, but I would miss simple, yet great ways of doing things.