Superbot is an IRC bot that has been designed with expansion and pluggability
in mind. 

It's currently on its third revision, the first was in java, the second in 
python, and the third in python using Twisted as the base. Superbot has a
plugin system inplace that lets the indivdual plugins control the bot with 
ease. There is also a safe-guard so that if a plugin crashes, or throws an
exception the bot will not go down. 

The main two focuses of Superbot are:
1)Robustness
    A faulty plugin should not be able to take out the bot
    Server splits should not be able to take out the bot
    Network lag and temporary disconnects should not take out the bot
2)Plugability
    Any feature desireable should be able to be implemented though the 
        plugin system
    The core of superbot should NOT be where the functionality is. The
        plugins should be the source of content and interaction.