Zzip
Zzip is a file compression/archiving utility (with Windows and Unix versions) and its file format. It was developed by Damien Debin.
The program doesn't seem to have been updated since June 2001, at which time the "unix version doesn't work any more" according to the revision history. The revision history also gives version 0.33a as when the "multiple-files-in-a-single-archive feature added", so it was apparently a single-file archiver before that.
Its compression scheme involves the Burrows–Wheeler transform. The source code is downloadable, so the file format could probably be figured out from that.
Zzip was designed to be used either as a standalone program or a library to embed in other programs.
It includes a utility to build self-extracting Zzip archives for the Windows platform.
Disambiguation
Not to be confused with zziplib, a library for ZIP format.
Identification
Presumably, all ZZip files start with the ASCII signature "ZZ".
For 0.36c at least, the next byte is a version number -- always 0x31 (ASCII "1") in v0.36c.
IDArc suggests that version 0x30 was also used.
IDArc also suggests that some files start with 'Z' 'Z' 0x20 0x00 0x00, which does not seem to fit the pattern of the later format versions.
