(Qt)-Backstep.py is commandline and graphical (Qt) backup software written in pure Python. It can back up any directory to CD-R(W), DVD-R(W), USB key, or another directory. It is a continuous backup solution. It works like a time machine. It contains a backup network server. It can send backups over the Internet or your network.
DragonDisk is a powerful file manager for S3 compatible cloud storage services, such as Amazon S3 and Google Cloud Storage. It allows you to back up, share, and organize your data thanks to an intuitive interface. Features include multiple windows; copy / move between Amazon S3 accounts; a multi-threaded HTTP/HTTPS engine; drag and drop; rename files and folders; filename filters; BiTorrent, time limited, and signed URLs; client side encryption; a metadata editor; ACL inheritance; detailed operations logs; and support for versioning.
SynchroDir is a backup and synchronization utility. Each backup is the subject of a recordable "backup project". This feature allows you to save projects corresponding to different computers, servers, external hard drives, USB keys, etc. You can also backup data of computer Y to computer Z from a controlling computer X. Each backup project includes an unlimited number of "jobs". At the end of the backup process, a log file is available. Each job has a source and a destination, each corresponding to a volume or a directory. The volume or directory must be "mounted", either locally or over the network.