Cerberus is a IRC bot written in PHP. It implements most basic functionality such as authorization and nick management. An accompanying web frontend 'hades' can be used in conjunction.
BitchX is an IRC client for Unixish systems, derived from ircII with influences from EPIC. It has built-in ANSI color support, not as pretty as Xchat but still easy to use; includes useful command aliases to reduce typing, notify, protection, bots, mass commands and channel tools, DCC and CDCC offering, and a link looker. It includes extended scripting capabilities, due to its large user base and lengthy development time. The included screen functionality allows to detach and reconnect to IRC se
BitlBee allows users to talk to people on the major instant messaging and microblogging networks (including MSN, Google Talk, AIM, and Twitter) from within any IRC client by emulating an IRC server. Virtual channels are created with all of the user's contacts in them, who can be talked to in the channel or in a query. Also, one can participate in group chats and chat rooms like they were normal IRC channels.