Deduplicator is a simple and efficient data deduplicator that works by hard linking files that have the same content. It is ideal for reducing the size of backups. It can save and restore intermediate results, so you can run it in a few short intervals, and allows you to review changes before they are committed to disk.
ESR Backup (Easy, Secure, Remote) is a backup system for UNIX and Linux that is easy to use and configure. It automatically performs full and incremental backups on files you choose, and automatically rotates and archives your backups, encrypts archives with a 448 bit key, and can store archives on a remote server via FTP or on the local file system.