OpenSSH - OpenSSH is a free version of the SSH connectivity tools that technical users rely on.
SFTPGo - Fully featured and highly configurable SFTP server with optional HTTP/S, FTP/S and WebDAV support - S3, Google Cloud Storage, Azure Blob
MobaSSH - Enhanced SSH server for Windows with Unix tools and much more
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
CerberusFTP - Cerberus FTP Server 8 The secure and reliable file transfer solution that you control.
KiTTY - KiTTY is a fork from version 0.70 of PuTTY. It adds extra features to PuTTY.