TuxBot is an IRC bot written in Lua. It was created to fit the requirements of the #linux channels on irc.oftc.net and irc.esper.net, but it is also used as a helpful bot in some other, non-Linux channels on other networks. The bot is able to link Linux channels on different networks by relaying messages between them. It is also able to kick flooders and to show the title of HTML pages after someone posted a link in a channel. Furthermore, TuxBot works as a raw multi-network IRC client for the console. There are some other features, such as the ability to extend TuxBot’s functionality using a simple module system.
mrtoms is an IRC bot written in Scala. It supports a very powerful and easy to use plugin system where plugins are compiled to and loaded from jar files. mrtoms comes with a Z-machine interpreter plugin so that games like Zork can be played collaboratively. It also includes an MPD control plugin and others.
Ibid is a multi-protocol, general purpose, instant messaging chat bot written in Python. It aims for a naturalistic interface rather than strict-syntax commands. Ibid understands many protocols, including IRC, Jabber/XMPP/Google Talk, Campfire, NMDC, and SILC. It also interacts over SMTP, HTTP, and various RPC protocols. Ibid aims to make plugins as easy as possible to write. It ships with a large collection of plugins for looking up information, performing conversions, storing factoids, delivering messages, and much more.
JTelIRC is an advanced IRC framework for Java. It is mainly intended for writing automated clients ("bots"), but may be used for normal clients as well. It provides an intuitive and well documented Java interface to IRC and makes it extremely easy to write advanced clients quickly.