MercuryOS [1, 2] appears to be simply a "speculative vision" with no proof of concept implementation, a manifesto rather than an actual system.

I read through its goals, and it seems that it is against current ideas and metaphors, but without actually suggesting any alternatives.

Perhaps an OS for the AI era, where the user expresses an intent and the AI figures out its meaning and carries it out?

[1] https://www.mercuryos.com/

[2] https://news.ycombinator.com/item?id=35777804 (May 1, 2023, 161 comments)