The IRC's Talking Robot
[ Please read https://sourceforge.net/p/darkbot/news/2014/01/darkbots-revitalization/ ] Darkbot is a portable IRC chat robot written in the C language that can be taught responses to user inquiries, and even have conversations with them. Darkbot was originally created by Jason Hamilton as an aid for help channels on Intenet Relay Chat.
OpenBNC is a fork of psyBNC, a widely used IRC Bouncer. It aims to implement a clustering system, MySQL db support, and several improvements such as a web interface, remote bouncer control, support for plugins and flexible control of user permissions.
Tcldrop is basically a clone of the Eggdrop IRC bot, but is being written purely in Tcl. The intention is to write a much more scriptable bot than Eggdrop is. It will run stand-alone or from any Tcl-enabled application (Tcl v8.5+).