This is my rapid prototyping JS "library" for building basic UI.
It is absolutely not viable for a production product. This is - at best - a minimalist tool for exposing UI in contexts where libraries or line count matter.
Personally, I use this in situations where content must be injected from outside into the DOM, as the single entrypoint function makes this entire library trivial to encode. This situation is most commonly encountered in Browser plugins or Userscripts.
There are zero external dependencies, and the entire library is under 100 LoC.