...It has support for IRC (v3.1) with planned support for XMPP.
It can be easily extended by means of its plugin API, and offers a host of features. It is known to function on any OS on which Ruby 1.9 functions (such as Linux, Mac OS X, BSD, Microsoft Windows, etc.).
A simple chat bot project for educational purposes! (OS X Only)
SimpleAiBot is created for educational purposes but it can grow out to something much bigger, however still educational. This project exists so other people can actually look at the code of a working chat bot and learn from it or even improve SimpleAiBot! If you're looking for this: this is it! Also don't hesitate to join and improve SimpleAiBot, better make your changes public and usable to everyone then experimenting on your own.
PS: More experienced AI developers are also welcome to...