I've been working on a project recently which is designed to sync multiple folders between multiple machines My project, called Fish Sync, allows users to backup a given number of folders across machines and it can sync specific folders to specific hosts.
Fish Sync has a GUI front end for easy administration, but also provides a command-line only daemon for people running headless servers. The daemon is basically a nice front end for rsync and secure shell (ssh), making routine, automated backups of specified folders.
If you're interested in trying it out, you can find a copy of Fish Sync here:
http://fishsync.sourceforge.net/
The back end is done in plain C++ and the GUI is done in Qt/C++. There are instructions on compiling & installing both the daemon and the front-end in the README file included with the source code. I don't believe anyone has made a Port for this yet, but hopefully in the near future....
Feedback is welcome, either here or at my e-mail address (included in the README file).
Sync files between computers
Threaded Mode