Under Windows 2000 and Xp, (the same code has no probleme under linux) i have a fonction wich create a socket like this let socket_acceuil = Unix.socket domain Unix.SOCK_STREAM 0 in Unix.bind socket_acceuil my_add_sock; Unix.listen socket_acceuil 1000; while true do message("Attente d un ami\n"); let (s_servA,caller)=Unix.accept socket_acceuil in ( message "ici" ; ignore ( Thread.create (reconnaitre_identite carnet s_servA) () ) ) done when i do a telnet on this socket for testing the program stop the message "Attente d un ami" is printed" but "ici" is not printed is there something special about Unix.accept under windows ? ps:message simply do a printf and a flush