fsbackup is an incremental backup creation utility. It supports backup compression and encryption. Backups can be stored on the local file system, and a remote host (via SSH, or FTP). Some additional scripts allow backup SQL tables from PostgreSQL and MySQL, save system configuration files, and a list of installed packages. Backed-up files can be recovered, and system packages can be reinstalled.
Virus Update Server (vsuserver) helps you maintain an updated mirror of the antivirus updates from the McAfee/Network Associates servers without having to download the entire list of updates every time a new antivirus update is available. It mirrors all the files needed for serveral OSes, and it also includes a FAQ on how to configure clients to update for their version of the product.
rsyncbackup is a handy tool for scheduled backups using rsync. rsyncbackup lets you easily setup multiple source folders and destinations, both locally, on your iPod or external firewire disk, or at a remote destination using ssh. rsyncbackup has no GUI, but is based on editing configuration files. The script is meant to be run in a crontab, so user interaction is not neccesary. Basic terminal skills are required to use the program.
Chiron FS is a FUSE based filesystem that implements replication at the filesystem level like RAID 1 does at the device level. The replicated filesystem may be of any kind you want; the only requisite is that you mount it. There is no need for special configuration files; the setup is as simple as one mount command (or one line in fstab).