A modified version of Supybot (an IRC bot)
Supybot is a robust (it doesn't crash), user friendly (it's easy to configure) and programmer friendly (plugins are extremely easy to write) Python IRC bot. It aims to be an adequate replacement for most existing IRC bots. It includes a very flexible and powerful ACL system for controlling access to commands, as well as more than 50 builtin plugins providing around 400 actual commands.
Limnoria is a project which continues development of Supybot (you can call it a fork) by fixing bugs and adding features.