You could do this with c# and a self contained publish. Likely many other languages as well.

Well that’s certainly an idea.

I’ve been working on a similar project since about 2016. My goals were slightly different. I wanted to use C++ and focus on minimalism, but still have solid content and capabilities. I finished a working version that hosts a JSON API of weather data and a web app to manage email aliases for a self-hosted mail server. It’s nothing fancy, but it generally works.

Iirc Tiddlywiki works similarly in that you can run an entire “wiki” in a single html file.

You could do this easily with Crystal and Kemal.