A proposal to replace JavaScript with something less evil:
https://john.ankarstrom.se/english/texts/replacing-javascript/
I, too, have been craving some kind of reduced-instruction-set version of #JavaScript, capable of only doing a handful of safe, well-standardized things.
The author does point out that the two can live side-by-side; I can block most legacy javascript with addons, and allow the safer replacement to run freely.
And by moving everything it does into HTML/CSS extensions, it looks a lot less painful to work with.