* I'm not planning on shutting it down at any point, the cost to operate it is very low (it's just a bunch of static files at its core). But I am personally also always weary to put stuff in online services, that's why I made it all open source: other than observable actually all the pieces are there (including editor and offline support), not just runtime/parser. You can download the files and check them into git, and edit them, and host them trivially. There's no "download all" button yet but if there's a demand for that why not :)

* Private notebooks make a lot of sense, and perhaps this is where it can be a viable product as well instead of just a useful open source tool? I have plenty of runway, but still it would be more sustainable if it could eventuallu pay my rent.. Similar to the (old) github model I mean (pay for team features / private notebooks you can share with some) with some reasonable limits? My main goal right now is to raise awareness for it. I think many many web developers especially would find the notebook paradigm really useful, but how do I show that?

* A lot of stuff.. auto save, I store every revision but currently you only can retrieve the latest, social features (e.g. recent notebooks, avatars), actual documentation (in notebooks of course).

If you have ideas or thoughts on where I should take this, do reach out! Email in my profile.