Copies directory hierarchies recursively into another location, by date (e.g. /home/ => /var/bkup/2002.12.13_04.27.56/). Permissions are preserved, so users with access to the backup directory can recover their files themselves.

File comparisons are done with MD5 checksums, so no changes go unnoticed.

Hard-links unchanged backuped files to old versions and identical files within the backuped tree.

Compresses large files (that don't match exclusion patterns).

Manages backups and removes old ones.