Tsync

I just discovered a new project called Tsync (http://tsyncd.sourceforge.net/).

"Tsync is a user-level daemon that provides transparent synchronization for one or more data volumes (directory trees) amongst a set of computers. Tsync uses a peer-to-peer architecture for scalability, efficiency, and robustness, which ensures that each node remains connected with all other connected nodes. The overlay network also provides a scalable means by which a Tsync node can learn about other hosts, besides the bootstrap host with which it was configured. Tsync uses strong authentication and encryption: hosts authenticate each other using the OpenSSH RSA-key authentication mechanism, and all data is encrypted using the symmetric key cryptography."