Fsync is a Perl script which allows for file synchronization between remote hosts, containing functionality similar to that of the rsync and CVS packages. Since fsync is a single Perl script, setting up file synchronization on a new machine is relatively simple. Communication between the hosts is via a socket mechanism or over an rsh (or ssh) connection, with the remote server started by rsh, by ssh or manually. The program was written with slow modem connections in mind. Fsync supports the concept of merging differences from local/remote hosts with hooks for tools to merge the trees. Fsync requires perl 5.004 or newer. This program is licensed under the GNU Public License.