This is basically a single library that has common routines used by rsbackup_client, rsbackup_p2p and rsbackup_server.
If you install any of these packages, this needs to be installed first. Currently, this consists only of rsbackup.pm, and most scripts will search for it in the parent of the bin directory. In other words, if rsbackup_p2p is installed in /opt/camp/rsbackup/rsbackup_p2p/, the parent directory (/opt/camp/rsbackup) will be searched first for this file (then, the standard perl lib path will be searched)
Download Here or use wget http://unixservertech.com/scripts/rsbackup_lib.tgz