ADTPro transfers disks to and from Apple II and Apple /// computers and the modern world using any of these communications methods: serial/USB, UDP via the Uthernet or LANceGS Ethernet cards, or audio via the Apple's cassette ports. ADTPro has comprehensive bootstrapping support for otherwise diskless Apple IIs. The home page includes extensive tutorials for getting started.
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).
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.
CLNoFault is a tool to protect your files or plain text. Using XOR encryption, it can quickly encrypt data using either a username and a password of your choice, or an external file that will serve as a key. Encrypted files can't be recovered in any way besides re-encrypting them with CLNoFault with the correct user/pass combination or keyfile. CLNoFault is the console-based interface for the NoFault library (like KNoFault for KDE), so it is useful in scripts.