zpaq 7.15 Incremental journaling archiver
ZPAQ is a command-line archiver for realistic situations with many duplicate and already compressed files. It backs up only those files modified since the last update. All previous versions remain untouched and can be independently recovered. Identical files are only stored once (known as de-duplication). Archives can also be encrypted.
ZPAQ is intended to back up user data, not entire operating systems. It ignores owner and group IDs, ACLs, extended attributes, or special file types like devices, sockets, or named pipes. It does not follow or restore symbolic links or junctions, and always follows hard links.