- published: 22 Oct 2007
- views: 251550
RAR stands for Roshal ARchive. It is a proprietaryarchive file format that supports data compression, error recovery, and file spanning. It was developed by a Russian software engineer, Eugene Roshal (the first letter of his surname contributing to the name of the archive format), and is currently licensed by win.rar GmbH.
The filename extension used by RAR is .rar
for the data volume set and .rev
for the recovery volume set. In previous versions, if a RAR-archive was split into many smaller files (a "multi-volume archive"), the smaller files used the extensions .rar
, .r00
, .r01
, .r02
etc.
Version 1 and 2 archive files were often used in conjunction with a parchive file archiver to create parity files for error recovery when using less-than-perfect file transmission and storage media such as newsgroups, satellite transmission, and optical discs. Version 3 has eliminated the need for third party post-processing.
The RAR compression utility is proprietary, with a closed algorithm. RAR is owned by Alexander L. Roshal, the elder brother of Eugene Roshal. Version 3 of RAR is based on Lempel-Ziv (LZSS) and prediction by partial matching (PPM) compression, specifically the PPMd implementation of PPMII by Dmitry Shkarin.