Chatmafia died because it was unmaintainable and buggy and the git with the source code mysteriously disappeared. After that, I created rty, which I stopped running on my server because no one was playing. I'd be willing to set it up again if there's some indication it would be used.
The Mafia logic was based on xylbot, but it was heavily modified.
The web app was adapted from a webIRC client, but I extended the IRC protocol to deal with other markup (like newlines!). It also included a setup creator, a GUI for Xylbot commands and other things I can't remember.
IIRC, altering or adding core mechanics to Xylbot was very complicated because of its structure, but the weird unreproducable bugs spawning from communication between the web server, the IRC server, and Xylbot was what broke me in the end.