The Unarchiver is a freedata decompression utility, which supports more formats than Archive Utility (formerly known as BOMArchiveHelper), the built-in archive unpacker program in OS X. It can also handle filenames in foreign character sets, created with non-English versions of other operating systems. The latest version requires Mac OS X v10.3.9 or higher. The Unarchiver does not compress files. The corresponding command line utilities unar and lsar run on Microsoft Windows, Linux, and Mac OS X.