Wikipedia
Duplicati
Duplicati is a backup client that securely stores encrypted, incremental, compressed remote backups of local files on cloud storage services and remote file servers. Duplicati supports not only various online backup services like OneDrive, Amazon S3, Rackspace Cloud Files, Tahoe LAFS, Google Docs but also any servers that support SSH/SFTP, WebDAV, or FTP.
Duplicati uses standard components such as rdiff, zip, AESCrypt and GnuPG. This allows to recover backup files even if Duplicati is not available. Released under the terms of the GNU Lesser General Public License (LGPL), Duplicati is free software.