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).
Autodl2 is a simple to manage and extensible file transfer system that can be configured simply using a configuration file. The system is designed to be lightweight and handle multiple file transfer protocols. Currently only SFTP is supported, though other systems can be added via a plugin system.