ARJ

This article is about the compressed file format. For other uses, see ARJ (disambiguation).

ARJ (Archived by Robert Jung) is a software tool designed in 1991 by Robert K. Jung for creating high-efficiency compressed file archives. ARJ is currently on version 2.86 for MS-DOS and 3.20 for Microsoft Windows and supports 16-bit, 32-bit and 64-bit Intel architectures.^[1]

Archived by Robert Jung
Filename extension	.arj
Uniform Type Identifier (UTI)	public.archive.arj
Developed by	Robert K. Jung
Initial release	1991; 34 years ago (1991)
Latest release	2.86 (MS-DOS), 3.20 (Windows)[1] May 1, 2012; 13 years ago (2012-05-01)[1]
Type of format	archive format
Open format?	Yes (patent expired)
Website	www.arjsoftware.com

ARJ was one of many file compression utilities for MS-DOS and Microsoft Windows during the early and mid-1990s. Parts of ARJ were covered by U.S. patent 5,140,321 (expired). ARJ is well-documented and includes over 150 command line switches.

File format support in other software

ARJ archives can be unpacked with various tools other than the ARJ software. There exists a free software re-implementation of the tool. A number of software utilities, including 7-Zip, Zipeg, and WinRAR can also unpack .arj files.^[2] For macOS, standalone utilities, such as DeArj and UnArjMac, are available.

See also

• List of archive formats
• Comparison of file archivers