It supports all versions of the RAR archive format, including RAR3 and RAR5.
It runs on macOS, and the command-line version, unar, also runs on Windows and on Linux, and is free software licensed under the LGPL.
The license permits its use to produce software capable of unpacking, but not creating, RAR archives, without having to pay a fee.
The software license agreements forbid reverse engineering. RAR files can be created only with commercial software WinRAR (Windows), RAR for Android, command-line RAR (Windows, MS-DOS, macOS, Linux, and FreeBSD), and other software that has written permission from Alexander Roshal or uses copyrighted code under license from Roshal.
Software is available for Microsoft Windows (named WinRAR), Linux, FreeBSD, macOS, and Android archive extraction is supported natively in Chrome OS. Main article: Comparison of file archivers Operating system support
Rar4 archives had to be parsed before opening as file names were spread throughout the archive, slowing operation particularly with slower devices such as optical drives, and reducing the integrity of damaged archives.