GOZERBOT is a channel bot that aids conversation in IRC channels and Jabber conference rooms. It's mainly used to serve RSS feeds and to have custom commands made for the channel. More then just a channel bot, GOZERBOT aims to provide a platform for the user to program his own bot and make it into something useful. This is done with a plugin structure that makes it easy to program your own. There are over 100 plugins already written and ready for use.
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.
JSONBOT is a remote event-driven framework for building bots that talk JSON to each other over XMPP. This distribution provides bots built on the JSONBOT framework for console, IRC, XMPP for the shell and WWW, and XMPP for the Google App Engine. A plugin infrastructure can be used to write your own functionality.
Ybot is erlang bot software inspired by Github hubot. It supports IRC and XMPP transports and is extensible with plugins. Plugins can be written with Python, Ruby, or shell. It supports IRC chat, XMPP multi user chat, and 37 signals Campfire chat. It can simultaneously run any number of bots on different transports.