There's a lot more to networking than this, but this should get you started. Chapter 6 of Programming Perl and the perlipc (1) manpage describe interprocess communication in general; the IO::Socket (3) manpage describes the object library; and the Socket (3) manpage describes the low-level interface to sockets. For the more intrepid programmers, the book Unix Network Programming by Richard Stevens (published by Addison-Wesley) covers the entire topic quite well. Be warned, however, that most texts on socket programming are written from the perspective of a C programmer.