ARJ
From Just Solve the File Format Problem
ARJ was one of the leading compression tools during the nineties. While it was a bit slower than PkZIP, it sported many more options, some of which were unique during that time (archives over multiple disks/volumes, fine-tuning of the compression algorithms used based on the data that was being compressed, recovery records to recover from simple transmission errors, etc.)
See also JAR (ARJ Software).
Software
Sample files
- http://cd.textfiles.com/20mnn/HPTEXT/PHRACK/
- The Silver Collection CDs have many ARJ files
Resources
- Wikipedia article
- The ARJ Archive File Format, from fileformat.info
- Another, slightly more verbose, file format description (apparently moved here)