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

ForeverSave - Data loss, caused by application crashes and unintentional overwriting will become history.

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

LBackup - An rsync based backup solution for *NIX based system(s), with a flexible scripting subsystem which...

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.

Retrospect - Retrospect Backup: Data Protection for Small Businesses. Windows, Mac, Linux, VMware, Hyper-V, Exchange, SQL, and Email. Servers and endpoints. Try for free for 45 days.