GoodSync - GoodSync provides highly reliable file backup and synchronization for both individuals and businesses.
Clonezilla - Clonezilla is a suite of software that's designed to allow you to back-up and image new hard drives with your data.
Syncthing - Syncthing replaces proprietary sync and cloud services with something open, trustworthy and...
Rufus - Rufus is a piece of software that allows you to transform a portable drive, like a flash drive or other USB drives, into a bootable drive that can be used for a variety of purposes. Read more about Rufus.
arRsync - arRsync is a tool that is designed for macOS that is used for transferring and synchronizing files between a computer and a storage drive.
Balena Etcher - Flash OS images to SD cards & USB drives, safely and easily.