you mean like amber smalltalk?

https://www.amber-lang.net/

https://en.wikipedia.org/wiki/Amber_Smalltalk

or more like https://squeak.js.org/ ?

https://squeak.js.org/demo/simple.html this is canvas not DOM/SVG. It doesn't support fonts/text. Its text support feels less janky than I expected, select, copy, paste work, but it is still not browser-native.

I don't know how to start Amber in the browser and couldn't find demos.