BackupPC is a free disk-to-disk backup software suite with a web-based frontend. The cross-platform server will run on any Linux, Solaris, or UNIX-based server. No client is necessary, as the server is itself a client for several protocols that are handled by other services native to the client OS.
License: Open Source
BackupPC is known for its ease of use and web-based interface, making it suitable for small to medium-sized environments. Bacula, on the other hand, offers a more scalable and flexible solution, making it ideal for larger enterprises with complex backup needs.