UUCP

GNU's UUCP system (written by Ian Lance Taylor) supports the `f', `g' (all window & packet sizes), `v', `G', `t', `e', Zmodem, & two new bidirectional (`i' & `j') protocols. With a BSD sockets library, it can make TCP connections. With TLI libraries, it can make TLI connections. Source is included for a manual (not yet published by the FSF).