SFTP is the Secure File Transfer Protocol. It is sort of a hybrid between old-school (unsupported) FTP and ssh.
You can use SFTP to send files to our service. It's much safer and more private than regular FTP because it encrypts both your password and your file transfers.
Since SFTP piggybacks on the ssh protocol, SFTP is also robust in the face of NAT routers and firewalls.
Due to its advantages, SFTP is the recommended method for uploading content to your site.
There are a number of SFTP applications listed in our member wiki. (Note that "Secure FTP," which only supported SSL/TLS-encrypted FTP, will not work for accessing our servers via SFTP.)