Hi, After writing a small tcp server in ocaml, I wanted to make it work asynchronously with Lwt. I changed the function handling the accept on the socket to look like this: let rec accept_connection sock:Unix.file_descr = let socket_thread = Lwt.return ( Unix.accept sock ) in let _ = Lwt.bind socket_thread ( fun (fd, caller) -> ignore(Lwt_io.printf "accepted\n%!"); (*let _ = set_nonblock fd in*) Lwt.return (readall fd) >>= fun a -> ignore(Lwt_io.printf "%s\n%!" a); ignore(Lwt.async (fun () -> Lwt.return (close fd) ) ); Lwt.return 0; ); in accept_connection sock The complete code is at http://pastie.org/10971189 . But it doesn't seem to work. The problems are: - nothing is printed on stdout - when I open 2 connections, the second can only be closed after the first has been closed. In the mean time I've discovered Lwt_unix, but before looking at it, I'd like to understand what's wrong in my current code. Can you spot errors in the code? General advice is also welcome! Thanks Raphael