Dar/mondorescue
DAR and Mondorescue are GPL'd Linux backup applications that appear to provide a complete backup solution comparable to the proprietary BackupEdge and to Storix Workstation Edition.
Dar
DAR provides a full set of features, e.g., file and filesystem full and incremental backups, include and exclude filters, splitting backups to allow storage on any media, random access to backups to restore individual files, compression, and more.
Mondorescue
Mondorescue is for disaster recovery. It provides bare-metal restores to recover from boot drive failures. It also has a differential backup feature.
Mondo's provides bare metal recovery from a disaster, and also allows cloning an entire system onto another drive. It provides interactive restore for cloning to a larger drive.
This HOWTO describes how to get started, and how to do a bare metal restore, but does not tell much else about restoring your data. What I found by trial and error is in Mondorestore.