Hello World (OCaml/F Sharp)
Hello World in Ocaml and F# (the program is identical for each). The "let () =" ensures that the return value of the following expression is "()" (the only value of type unit). This detects e.g. missing arguments (it is unecessary for such a simple program but better start with good habits!).
<<hello.ml>>= let () = print_endline "Hello World!"