Good read. I really liked how the author concretely defined the things they use in OCaml, instead of just saying "functional programming" and waving their hands.
"Algebraic data types!" [waves hands vigorously]. Seriously though, I agree. It's a very solid run-down of all the main ways OCaml is cool. I'll probably link people here if they ask my about why they should bother with OCaml.
