FileZilla Server - Download FileZilla Server 0.9.60.2 for Windows
CompleteFTP by EnterpriseDT - CompleteFTP is a secure FTPS and SFTP server for Windows.
ProFTPD - The Official ProFTPD web site. ProFTPD is a high-performance, extremely configurable, and most of all a secure FTP server, featuring Apache-like configuration and blazing performance.
SFTPGo - Fully featured and highly configurable SFTP server with optional HTTP/S, FTP/S and WebDAV support - S3, Google Cloud Storage, Azure Blob
vsftpd - Very secure FTP Daemon, a secure, fast FTP server for UNIX systems, including Linux.
Titan FTP Server - Windows FTP Server with SFTP and SSL. Includes events automation, host key support, and strong security.