Duplicati - Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.

N2WS Cloud Protection Manager - N2WS is the leading Enterprise-class disaster recovery, and backup solution specifically made for Amazon EC2 servers.

snaprd - Snaprd is a program that helps you to make snapshot backups using rsync.

VSquare - Vsquare is a Vmware and Hyper-V-based data protection, disaster recovery, and business continuity solution that provides businesses with a complete, affordable solution for protecting their data and ensuring continuity in the event of a disaster.

rsync - rsync is a file transfer program for Unix systems. rsync uses the "rsync algorithm" which provides a very fast method for bringing remote files into sync.

Bacula Enterprise - A physical, virtual and cloud data center backup software for data centers. Bacula Enterprise Edition is the best open source backup software.