Areca is a file backup system that supports data compression (zip / zip64 format) and encryption, incremental backups, FTP/SFTP file transfer, delta storage mode, and many other features. It includes a transaction mechanism, which guarantees the integrity of your backups. Two user interfaces are available: a command-line interface (useful for backup automation) and a graphical user interface (useful for backup administration).
BAR is backup archiver program to create compressed and encrypted archives of files that can be stored on a hard disk, CD, DVD, BD, or directly on a server via FTP, SCP, or SFTP. A server mode and a scheduler are integrated for making automated backups in the background. A graphical front end that can connect to the (remote) server is included.
Bacula is a set of programs that allow you to manage the backup, recovery, and verification of computer data across a network of different computers. It is based on a client/server architecture and is efficient and relatively easy to use, while offering many advanced storage management features that make it easy to find and recover lost or damaged files.
Bork is a very small, cross-platform file encryption utility using a password-based RC4 algorithm. It is designed to be included in source code form along with the files it encrypts for long-term storage (eg on CD-R). Its minimal external dependencies are designed to make it fairly futureproof.