This is the file README for the gzip distribution, version 0.6.

gzip (GNU zip) is a compression utility designed to be a replacement
for 'compress'. Its main advantages over compress are much better
compression and freedom from patented algorithms.  The GNU Project
intends to make this the standard compression program for its system.

gzip currently uses by default the LZ77 algorithm used in zip 1.9 (the
portable pkzip compatible archiver). The gzip format was however
designed to accomodate several compression algorithms.  Future
versions of gzip may optionally support compression with the LZW
algorithm to produce files compatible with compress 3.0 to 4.2.

gunzip can currently decompress files in gzip deflate format, zip
format or 'compress' format. The detection of the input format is
automatic.  When using the first two formats, gunzip checks a 32 bit
CRC. (The 'compress' format does not allow this.)

gzip produces files with a .z extension. This was chosen to mimic the
'compress' .Z extension. Using exactly the same extension would have
caused too much confusion. Using a completely different extension
would have forced changes in other programs such as GNU tar (which has
a -z option).  The .z extension is already used by the 'pack'
Huffman encoder, but this program is rarely used because it does not
compress well.

This version 0.6 is a beta release. Several planned features are not
yet supported (see the file TODO). The lzw compression code is not
provided in this version to avoid the IBM patent 4,814,746 and the
Unisys patent 4,558,302.  The encryption code is not provided because
of the US export rules.

See the file INSTALL for installation instructions. See the file NEWS
for a summary of changes since 0.5.

WARNING: at least on the NeXT, "gcc -finline-functions" is broken.
gzip produces valid .z files but they are much too large because
the string matching code misses most matches. Use "gcc -O" instead.
Use "make test" to check that gzip was compiled correctly.

Please send all comments and bug reports by electronic mail to:
   Jean-loup Gailly <jloup@chorus.fr>

or, if this fails, to bug-gnu-utils@prep.ai.mit.edu.
Bug reports should ideally include:

    * The complete output of "gzip -V" (or the contents of revision.h
      if you can't get gzip to compile)
    * The hardware and operating system
    * The compiler used to compile
    * A description of the bug behaviour
    * The input to gzip, that triggered the bug

This program is free software, you can redistribute it and/or modify
it under the terms of the GNU General Public License, a copy of which
is provided under the name COPYING.

Many thanks to those who provided me with bug reports and feedback.
See the files THANKS and ChangeLog for more details.