ZLIB DATA COMPRESSION LIBRARYzlib 1.2.11 is a general purpose data compression library.  All the code isthread safe.  The data format used by the zlib library is described by RFCs(Request for Comments) 1950 to 1952 in the fileshttp://tools.ietf.org/html/rfc1950 (zlib format), rfc1951 (deflate format) andrfc1952 (gzip format).All functions of the compression library are documented in the file zlib.h(volunteer to write man pages welcome, contact zlib@gzip.org).  A usage exampleof the library is given in the file test/example.c which also tests thatthe library is working correctly.  Another example is given in the filetest/minigzip.c.  The compression library itself is composed of all sourcefiles in the root directory.To compile all files and run the test program, follow the instructions given atthe top of Makefile.in.  In short "./configure; make test", and if that goeswell, "make install" should work for most flavors of Unix.  For Windows, useone of the special makefiles in win32/ or contrib/vstudio/ .  For VMS, usemake_vms.com.Questions about zlib should be sent to <zlib@gzip.org>, or to Gilles Vollant<info@winimage.com> for the Windows DLL version.  The zlib home page ishttp://zlib.net/ .  Before reporting a problem, please check this site toverify that you have the latest version of zlib; otherwise get the latestversion and check whether the problem still exists or not.PLEASE read the zlib FAQhttp://zlib.net/zlib_faq.html before asking for help.Mark Nelson <markn@ieee.org> wrote an article about zlib for the Jan.  1997issue of Dr.  Dobb's Journal; a copy of the article is available athttp://marknelson.us/1997/01/01/zlib-engine/ .The changes made in version 1.2.11 are documented in the file ChangeLog.Unsupported third party contributions are provided in directory contrib/ .zlib is available in Java using the java.util.zip package, documented athttp://java.sun.com/developer/technicalArticles/Programming/compression/ .A Perl interface to zlib written by Paul Marquess <pmqs@cpan.org> is availableat CPAN (Comprehensive Perl Archive Network) sites, includinghttp://search.cpan.org/~pmqs/IO-Compress-Zlib/ .A Python interface to zlib written by A.M. Kuchling <amk@amk.ca> isavailable in Python 1.5 and later versions, seehttp://docs.python.org/library/zlib.html .zlib is built into tcl:http://wiki.tcl.tk/4610 .An experimental package to read and write files in .zip format, written on topof zlib by Gilles Vollant <info@winimage.com>, is available in thecontrib/minizip directory of zlib.Notes for some targets:- For Windows DLL versions, please see win32/DLL_FAQ.txt- For 64-bit Irix, deflate.c must be compiled without any optimization. With  -O, one libpng test fails. The test works in 32 bit mode (with the -n32  compiler flag). The compiler bug has been reported to SGI.- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works  when compiled with cc.- On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is  necessary to get gzprintf working correctly. This is done by configure.- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with  other compilers. Use "make test" to check your compiler.- gzdopen is not supported on RISCOS or BEOS.- For PalmOs, seehttp://palmzlib.sourceforge.net/Acknowledgments:  The deflate format used by zlib was defined by Phil Katz.  The deflate and  zlib specifications were written by L.  Peter Deutsch.  Thanks to all the  people who reported problems and suggested various improvements in zlib; they  are too numerous to cite here.Copyright notice: (C) 1995-2017 Jean-loup Gailly and Mark Adler  This software is provided 'as-is', without any express or implied  warranty.  In no event will the authors be held liable for any damages  arising from the use of this software.  Permission is granted to anyone to use this software for any purpose,  including commercial applications, and to alter it and redistribute it  freely, subject to the following restrictions:  1. The origin of this software must not be misrepresented; you must not     claim that you wrote the original software. If you use this software     in a product, an acknowledgment in the product documentation would be     appreciated but is not required.  2. Altered source versions must be plainly marked as such, and must not be     misrepresented as being the original software.  3. This notice may not be removed or altered from any source distribution.  Jean-loup Gailly        Mark Adler  jloup@gzip.org          madler@alumni.caltech.eduIf you use the zlib library in a product, we would appreciate *not* receivinglengthy legal documents to sign.  The sources are provided for free but withoutwarranty of any kind.  The library has been entirely written by Jean-loupGailly and Mark Adler; it does not include third-party code.If you redistribute modified sources, we would appreciate that you include inthe file ChangeLog history information documenting your changes.  Please readthe FAQ for more information on the distribution of modified source versions.