Bitmessage is a P2P communications protocol used to send encrypted messages to another person or to many subscribers. It is decentralized and trustless, meaning that you need-not inherently trust any entities like root certificate authorities. It uses strong authentication, which means that the sender of a message cannot be spoofed, and it aims to hide "non-content" data, like the sender and receiver of messages, from passive eavesdroppers like those running warrantless wiretapping programs.
In this version the default known nodes have been removed and the PoW difficulty decreased to make the client more suitable for a friend to friend netork.
Bitmessage is a collaborative project. You are welcome to submit pull requests although if you plan to put a non-trivial amount of work into coding new features, it is recommended that you first solicit feedback on the DevTalk pseudo-mailing list: BM-2D9QKN4teYRvoq2fyzpiftPh9WP9qggtzh