Syncthing - Syncthing replaces proprietary sync and cloud services with something open, trustworthy and...
Clonezilla - Clonezilla is a suite of software that's designed to allow you to back-up and image new hard drives with your data.
Dropbox - Online Sync and File Sharing
Macrium Reflect - Macrium Software - the creators of Macrium Reflect backup, imaging and cloning software.
Microsoft OneDrive - Secure access, sharing & file storage
AOMEI Backupper - AOMEI Backupper is a software created to help a person backup, restore, clone, and sync their entire Windows system.