Here is a list of some A.I Chatterbots that i've made, those who are intrested in A.I, Virtual Character, etc, please take a look
First you need the Free Verbots Player, to download the chatbots you need to register on the Verbots forum (which is also free, (a phpbb forum, just like here)
Verbot Player is also on the download.com LINK
1 ) Friend4u
2) Psychic Bot
Also there is a Solar System Knowledge Base
Solar System
Verbots technology is now going "open source" and this is the best software out there in the category of A.I chatterbot/Virtual Character development