[brumar]

Very good. I was wondering why nobody did something like that before. At least this was my conclusion from my google searches few months ago. From a design perspective, I don't like storing state in the DOM itself, I would have find much more flexible to have the state in a json as a single source of truth and use reactive patterns such as state change => ui change and not hiting the DOM directly. That sounds like big framework things, but it saved me from acute headaches in a personal similar framework I did for self-contained apps. It was not HTML but I thought I would apply the same logic if I had to do it for html apps too.

[modeless]

I guess your searches missed Tiddlywiki. I think there have been a couple of other takes on the concept too.

[clemensnk]

Also our Webstrates (https://webstrates.net) system stores state in the DOM itself. But it's more a system for research prototyping than publishing web pages.