TCP/IP packet repeater in the application layer

 It repeats TCP and UDP packets from inside to outside of a firewall, or from
 outside to inside.
 Stone supports SSL. stone can encrypt/decrypt packets with OpenSSL library.
 Stone can also be a tiny http proxy.
 POP -> APOP conversion. With stone and a mailer that does not support APOP,
 you can access to an APOP server.