> "The thing that nobody told me is that OCaml’s runtime cannot do two things at once. It has a Python-style GIL."

That's the reason I kick-started a crowd sourcing effort to collect a table of such basic facts among compiled "systems" languages:

https://docs.google.com/spreadsheets/d/1BAiJR026ih1U8HoRw__n...

(There's still a lot of gaps in there which you are welcome to help fill out)