vsftpd - Very secure FTP Daemon, a secure, fast FTP server for UNIX systems, including Linux.
Forklift - The most advanced dual pane file manager and file transfer client for macOS.
WinSCP - WinSCP is an open source free SFTP client and FTP client for Windows.
FileZilla Secure - A modified version of Filezilla dedicated to keeping your FTP passwords secure.
PyroBatchFTP - PyroBatchFTP/SFTP helps you to exchange files with internet SFTP servers in an automated way by processing scripts. e.G. to automatically update documents on web servers.
Cyberduck - A libre FTP, SFTP, WebDAV, S3, Backblaze B2, Azure & OpenStack Swift browser.