vsftpd, (or very secure FTP daemon), is an FTP server for Unix-like systems, including Linux. It is licensed under the GNU General Public License. It supports IPv6 and SSL.
vsftpd supports explicit (since 2.0.0) and implicit (since 2.1.0) FTPS.
vsftpd is the default FTP server in the Ubuntu, CentOS, Fedora, NimbleX, Slackware and RHEL Linux distributions.