Duplicati - Free backup software to store backups online with strong encryption. Works with FTP, SSH, WebDAV, OneDrive, Amazon S3, Google Drive and many others.
DAR - Disk Archive Home Page
snaprd - Snaprd is a program that helps you to make snapshot backups using rsync.
GNU tar - GNU tar saves many files together into a single tape or disk archive, and can restore individual...
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.
bzip2 - bzip2 is a file compressor that uses the Burrows–Wheeler algorithm.