Bacula is a set of computer programs that permit managing backup, recovery, and verification of computer data across a network of computers of different kinds. Based on Source Forge downloads, Bacula is the most popular Open Source backup program.
Backup your data! - Easy and save. Each new backup is in its own folder - only changed or new files are stored again. A "Current"-folder is hard linked to the physical backup files. Deleted files are hold in a separate folder - nothing get lost.