I learned about 0mq a few years back, found myself wondering why it had such an air of quality. Then I found Hitnjens' writing, only to learn that he had been gone for a while. I was surprised by my sense of loss.
Fwiw, not that it mattes a lot, I think most of that sense of quality in ZeroMQ is due to the very tasteful efforts of its main author, Martin Sustrik (https://www.250bpm.com/). Pieter Hintjens sortof stewarded the project but, I believe, didn't code all that much on it.
I did use the Xitami webserver in anger or years back in the early 2000s though, and that very much was Pieter's work! It was amazing!
