Syncplify.me Server is the secure FTP, FTPS, and SFTP server for Windows by Syncplify, Inc. Powerful, secure, yet very easy to configure, Server simplifies regulatory compliance and operation of a secure file transfer server. And it's totally free for personal use, including lifetime updates and upgrades (paid licenses available for other uses).
Main features: Supports plain FTP, explicit FTPS (TLS), implicit FTPS (TLS), and SFTP file transfer protocols. Also provides a basic secure shell (SSH-2) and forwarding tunnels support. Runs as a system service. Supports large files (> 4 GB). Advanced features: PKI authentication with multiple key-pairs per user. Advanced FTP(S) and SFTP security settings. Automatic blacklist. Real-time monitor. Virtual folders with per-folder security. IP-based and per-user security (white-lists). Powerful event-handling subsystem. Easy graphical Configuration Manager. Command-line Interface configuration tool.
The freeware version accepts only 1 connection per protocol, and can be used only for personal use