Cyberduck is a free open source file transfer client for Windows and Macintosh desktops.

Cyberduck offers support for FTP, FTPS, SFTP, Amazon S3, Rackspace Cloud Files, Google Storage for Developers and Amazon Cloud Front.  Cyberduck features sychronization across multiple server types and support for many languages.

Cyberduck’s official site is cyberduck.ch.  It is licensed under GNU.