Back In Time is a simple backup system for Linux (Gnome & KDE4). The backup is done by taking snapshots of a specified set of directories. (GPL)

Cedar Backup manages backups for a pool of local and remote machines. Backups can be written to CD or DVD. A variety of backup sources are supported. (GPL)

Déjà Dup is a simple backup tool. It hides the complexity of doing backups the 'right way' and uses duplicity as the backend. (GPL)

DeltaCopy is a Windows Friendly wrapper around the Rsync program. (GPL)

dkopp is a free open source Linux program used to copy or back-up disk files to DVD. (GPL)

Duplicity backs directories by producing encrypted tar-format volumes and uploading them to a remote or local file server. (GPL)

LuckyBackup is an application for data back-up and synchronization powered by the rsync tool. It is simple to use, fast, safe, reliable and fully customizable. (GPL)

rdiff-backup backs up one directory to another, possibly over a network. (GPL)