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
The Tcl IRCd is a small IRC server written in Tcl. It is very simple to modify. It is not a full implementation of the IRC protocol, but it's enough to create channels, talk in public or private, change topic, nick, and other basic operations. No configuration is required. The server is designed so that it can reload an updated version of itself at runtime without closing client connections.