rsbackup-cs is a client/server backup system which uses rsync over ssh to synchronize a client file system to a server. It used to be called just rsbackup, but another project has started using that, so we renamed it to rsbackup-cs.
We have used it for about 20 years for our backup clients at Daily Data, and the installer is fairly primitive though the program is very mature.
rsbackup-cs uses Perl to manage both the client and server, and has been tested on Linux and BSD.