FileZilla Server - Download FileZilla Server 0.9.60.2 for Windows
Restic - Easy: Doing backups should be a frictionless process, otherwise you are tempted to skip it.
vsftpd - Very secure FTP Daemon, a secure, fast FTP server for UNIX systems, including Linux.
Duplicati - Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.
Baby FTP Server - The simplest FTP server to setup. No authentication required.
rsync - rsync is a file transfer program for Unix systems. rsync uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync.