Besides the obvious functions in the perlfunc manpage, you should also check out the modules file at your nearest
CPAN site. (See the perlmod manpage or best yet, the Perl FAQ for a description of what
CPAN is and where to get it.) Section 5 of the modules file is devoted to ``Networking, Device Control (modems), and Interprocess Communication'', and contains numerous unbundled modules numerous networking modules, Chat and Expect operations,
NNTP, Proxy, Ptty,
SMTP, Telnet, Threads, and ToolTalk--just to name a few.