Pest is a peer-to-peer network protocol intended for IRC-style chat. It is designed for decentralization of control, resistance to natural and artificial interference, and fits-in-head mechanical simplicity -- in that order.
Blatta is written and maintained by thimbronion (WOT: thimbronion) and implements a large subset of the current spec. Blatta is written in Python 2.7 and uses SQLite3 for the database. Blatta is a work in progress and is updated regularly.