JAIMBot is a modular architecture for providing services through an AIM client. It contains a generic AIM library and a Bot which uses this library to provide such services as Offline Messaging, Lists, Weather, Headlines, Stock Quotes, TV Listings, and an AI chatterbot. You can try out this project with a live AIM bot called JavaAIMBot. Send it "help" as an instant message to see what it can to.
daim is an IM client and library that supports many features, including add-ins, AIM proxy, buddy icons, chat, direct IM, file transfer, file sharing, send buddy list, and Trillian secureIM. It also supports retrieving News and Stocks, and scripting through Apache BSF. It also supports ICQ, can emulate Apple's iChat client, and supports iChat available messages as well.
Twisted Words provides implementations of a handful of IM protocols, including IRC, MSNP8, OSCAR, TOC, and Jabber. It also comes with a multi-protocol server built around a few simple interfaces, the goal of which is to facilitate implementations of novel servers, clients, and bots. Out of the box, it comes with server that accepts connections over IRC and PB and seeks out installed third-party plugins to support other interfaces (for example, a Nevow LivePage-based Web interface).
Push Puppet Toy is a computer-controlled puppet that stands to attention when a friend joins an IRC channel or comes online on IM, and collapses when he leaves. The concept is very similar to the Availabot (http://availabot.com/), but works under Linux. Schematics, firmware for the puppet, and plugins for Gaim and XChat to control the puppet are provided.