IRC Channel Relay Bot allows you to have an IRC channel span multiple IRC networks. It relays public and private messages, informs you about people joining and leaving the channel, and passes topics across networks (if you op it). It has minimal ability to help protect the channel.
NetPlug is an extensible multi-connections, multi-protocol, network client program, written in pure Tcl/Tk. Includes a complete Irc client plug in that you should love if you like IrcII 'classic' look & feel (plus customizable style/colors scheme, sound,... Now includes full DCC support (with GUI), ircII like aliases and improved scripting (Tcl!), keywords (your nick...) highlighting, and more
jIRCii is a cross platform Internet Relay Chat client. It is fully scriptable using a Perl-like language called sleep. The focus is to provide a console client experience with the advantages of a solid GUI. It includes DCC/CTCP support, the ability to connect to SSL servers, and over 65 built-in commands.