First thing I asked myself was "What framework is Hydrogen?" and I briefly guessed it was the next trendy GUI toolkit.
I first guessed it was the chemical, then remembered I was on HN, and did a double take also thinking it was a Rust rewrite of some fancy library, or something.
I was (pleasantly?) surprised at the outcome, I guess...
That was also my assumption before clicking the link
As a member of the rust evangelism strike force, I was thoroughly confused.
The username of the person posting it (rustoo) seems appropriate too, but that might just be coincidental!