Disk Archiver
From Just Solve the File Format Problem
Disk Archiver (dar) was created (originally for Linux, but now available for a number of systems) as a replacement for the venerable Tape Archive (TAR) format used in Unix-style operating systems. It supports compression as well as multiple-file archiving, and can split archives across multiple disks, among other features.
Identification
Files begin with bytes 00 00 00 7b
.