As jggimi stated, SFTP server is built into SSHD, and enabled by default last I looked, it can be disabled in the sshd_config file. There are also GUI clients for Windoz(WinSCP) and MAC(Fugu) to name a couple, most *nix's come with a command line client. I too prefer VSFTPD and it is very easily installed and configured and fast as all hell