gzip

tool, compression GNU compression utility. Gzip reduces

the size of the named files using Lempel-Ziv LZ77compression. Whenever possible, each file is replaced by one

with the filename extension ".gz". Compressed files can be

restored to their original form using gzip -d or gunzip or

zcat.

The Unix "compress" utility is patented (by two separate

patents, in fact) and is thus shunned by the GNU Project since

it is not free software. They have therefore chosen gzip,

which is free of any known software patents and which tends

to compress better anyway. All compressed files in the GNU

anonymous FTP area (gnu.org/pub/gnu) are in gzip

format and their names end in ".gz" (as opposed to

"compress"-compressed files, which end in ".Z").

Gzip can uncompress "compress"-compressed files and "pack"

files (which end in ".z"). The decompression algorithms are

not patented, only compression is.

The gzip program is available from any GNU archive site in

shar, tar, or gzipped tar format (for those who already

have a prior version of gzip and want faster data

transmission). It works on virtually every Unix system,

MS-DOS, OS/2 and VMS.