I mean the design of the user-facing API: https://github.com/EmilStenstrom/justhtml/blob/main/docs/api...

See also the demo app I vibe-coded against their library here: https://tools.simonwillison.net/justhtml - that's what initially convinced me that the API design was good.

I particularly liked the design of JustHTML's core DOM node: https://github.com/EmilStenstrom/justhtml/blob/main/docs/api... - and the design of the streaming API: https://github.com/EmilStenstrom/justhtml/blob/main/docs/api...