Bacula
Bacula is a set of Open Source, enterprise ready, computer programs that permit you (or the system administrator) to manage backup, recovery, and verification of computer data across a network of computers of different kinds. Bacula is relatively easy to use and efficient, while offering many advanced storage management features that make it easy to find and recover lost or damaged files. In technical terms, it is an Open Source, enterprise ready, network based backup program.
It comes by night and sucks the vital essence from your computers.
I have over fifteen years experience in systems and network configuration and support. For most of that time I have been working with Open Source Software, and believe that Open Source software provides the best solutions for business, educational and personal use.