Beaver is a simple concurrent backup system with snapshotting. It is based on a simple list of servers, a file of configuration options, and lists of things to be excluded or included. More powerful configuration options are available in the configuration files. Different copies of beaver backup can be run on the same server with different configuration files. Beaver backup is normally run by cron on a central backup box and uses keychain for remote authentication.
PYBAG implements a portable bag and is intended for fast synchronization and backup. It lets you use a portable digital storage device to carry your electronic documents similar to the way you can use a bag to carry paper documents. You can synchronize the bag with your original files easily. If a synchronization conflict occurs, it will be reported. You can specify rules for automatic conflict resolution. With PYBAG, you can backup files and synchronize any changes made to the original files with the bag. The synchronization process will only copy changed files. The program is cross-platform and independent from the OS and filesystem. You may easily synchronize files between Windows and Linux, for example. Symbolic links are supported on all systems (if the OS or filesystem does not support symlinks, then they are emulated). This program has a GUI and a command line interface.
Backupninja allows you to coordinate system backup by dropping a few simple configuration files into /etc/backup.d/. Most programs you might use for making backups don't have their own configuration file format. Backupninja provides a centralized way to configure and schedule many different backup utilities.
RVM is an archive manager that uses rsync to manage backups of multiple clients across multiple logical partitions (vaults). It has some features that some other rsync-based backup schemes lack, such as being written in C++, needing no scripts or other programs than rsync and any binaries on which rsync depends (such as SSH), the ability to manage multiple instances of rsync connections to separate clients in parallel, the ability to use multiple logical partitions (vaults) in a configurable fashion for purporses of redundancy and added reliability, and the use of hard links for files that have not changed from one archive to the next.
Antida is data synchronization and backup software that works on any network that has Internet access. It allows automated backup to USB or any storage device. It can send files to any Web-enabled phone. Only a browser and Internet connection are required, with Antida on the other side of the data transfer. It can communicate with devices behind routers and firewalls on WANs.