Unix system programming in OCaml

“This document is an introductory course on Unix system programming, with an emphasis on communications between processes. The main novelty of this work is the use of the OCaml language, a dialect of the ML language, instead of the C language that is customary in systems programming. This gives an unusual perspective on systems programming and on the ML language…”

http://ocamlunix.forge.ocamlcore.org/ocamlunix.html