rdup is a utility inspired by rsync and the Plan9 way of doing backups.

rdup itself does not backup anything; it only prints a list of the names of
files that have changed since the last backup. It also handles files that are
removed, allowing for correct incremental backups.

Example scripts that implement a backup strategy are included.
(These scripts require GNU date and cp, which are not installed by
this FreeBSD port.)

WWW: http://miek.nl/projects/rdup