ARJZ

ARJZ is a compressed archive utility, primarily developed by Bulat Ziganshin (Булат Зиганшин). Its native file format is an incompatible variant of ARJ.

Format details
ARJZ's main features seem to be:
 * Increase ARJ's 26K history window to 32K, like LHA's "lh6" method. Indicated by ARJ's minimum archiver version to extract field set to 50.
 * Increase the history window to 64K, like LHA's "lh7" method. Indicated by ARJ's minimum archiver version to extract field set to 51.
 * Some sort of audio-targeted compression technique, enabled by the  option. Indicated by ARJ's "file type" field set to 9.

Identification
Like ARJ, an ARJZ file starts with bytes, and has  at offset 10.

Unlike ARJ, ARJZ files are observed to have  at offset 5 (meaning archiver version = 51).

Software

 * [ ARJZ 0.15 alpha] - Includes binaries for DOS, OS/2, and Windows NT console.
 * [ UNARJZ 0.15 beta]
 * ARJZ 0.06 source code: FTP mirror - fidonet.org.ua - 2015-02-12 → fidonet.org.ua/pub/sources/arjz006s.rar (or )