The Unarchiver is a

proprietary freeware Freeware is software, most often proprietary, that is distributed at no monetary cost to the end user. There is no agreed-upon set of rights, license, or EULA that defines ''freeware'' unambiguously; every publisher defines its own rules for the f ...

data decompression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either Lossy compression, lossy or Lossless com ...

utility, which supports more formats than

Archive Utility This is a list of macOS built-in apps and system components. Applications App Store The Mac App Store is macOS's digital distribution platform for macOS apps, created and maintained by Apple Inc. based on the iOS version, the platform was an ...

(formerly known as BOMArchiveHelper), the built-in archive unpacker program in

macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

. It can also handle filenames in various

character encodings Character encoding is the process of assigning numbers to graphical characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using digital computers. The numerical values that ...

, created using

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

versions that use those character encodings. The latest version requires Mac OS X Lion or higher. The Unarchiver does not compress files. The corresponding command line utilities unar and lsar is

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

licensed under the

LGPL The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own ...

run on

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

, and macOS. A main feature of the Unarchiver is its ability to handle many old or obscure formats like StuffIt as well as

AmigaOS AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early version ...

disk images and LZH / LZX archives, and so on. This is credited in its source code to the use of libxad, an Amiga file format library. Ågren also worked to reverse engineer the StuffIt and StuffIt X formats, and his code was one of the most complete open source implementations of these proprietary formats.

References

External links

The Unarchiver's Website

unar, lsar source code repository

Circlesoft Website

Version for Mac OS X 10.6.8 and earlier

Old Source Code as ZIP
File archivers Data compression software macOS software {{mac-software-stub