Filename extension .arj Developed by Robert K. Jung | Uniform Type Identifier (UTI) public.archive.arj Type of format archive format | |
ARJ (Archived by Robert Jung) is a software tool designed by Robert K. Jung for creating high-efficiency compressed file archives. ARJ is currently on version 2.86 for DOS and 3.20 for Windows and supports 16-bit, 32-bit and 64-bit Intel architectures.
ARJ was one of two mainstream archivers for DOS and Windows during the early and mid-1990s, with PKZIP being its competition. Parts of ARJ were covered by U.S. Patent 5,140,321. Generally ARJ was less popular than PKZIP, but it did enjoy a niche market during the BBS era and in the warez scene. This was largely due to ARJ's creation and handling of multi-volume archives (archives which are split into smaller files which are then suitable for dial-up transfers and floppy distribution) being more robust than PKZIPs.
File format support in other software
ARJ compressed files with the Filename extension .arj can be unpacked with various tools other than the ARJ software. There exists a free software re-implement of the tool. The software 7-Zip and Zipeg can also unpack .arj files. For Mac there exists a standalone utility UnArjMac.