Attic is a deduplicating backup program. The main goal of attic is to provide an efficient and secure way to back up data. The data deduplication technique used makes Attic suitable for daily backups since only actual changes are stored. Main features: space efficient storage, optional data encryption, and off-site backups.
pyReScene is a tool that recreates original RARs by backing up the metadata. It is a port of ReScene .NET to Python. It provides a mechanism for backing up and restoring the metadata from "scene" released RAR files. RAR archive volumes are rebuilt using the stored metadata in the SRR file and the files extracted from the RAR archive. pyReScene consists of multiple related tools: pyReScene Auto to create a complete SRR with one simple command, pyReSample to recreate sample files, and pyReScene Usenet to create SRR files on the fly from Usenet postings. Lots of other small scripts for managing SRR and SRS files are available too.
SNeBU (Simple Network Backup Utility) is a backup system that supports incremental snapshot-style backups to disk-based storage. The project has been rewritten in C, and stores its backup catalog in an SQLite database. It features file level deduplication (including across multiple clients), compressed storage, incremental-forever snapshot style backups, simple setup, and utilizes standard TAR format. The client side consists of a simple shell script, which can be easily installed and adapted as needed. The server side is a single binary plus a config file, which can sit on a remote server and be accessed over SSH.
zrep provides an easy-to-use program to manage zfs filesystem replication and failover. No configuration files are required. The program is developed under Solaris, but may work with any up to date zfs implementation. The executable is a single script. Initialization does a full data copy, but subsequent syncs are incrementals. It uses internal locking to make sure there is no danger of overlap if you just shove it in cron to run every minute. Design target is more "near-time replication", since the sync can be run every minute or more. However, it could conceivably be used for "backup" purposes as well.
(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.