Current version (1.2.3):

zlib123.zip - zlib-1.2.3.tar.gz - sources of zlib

• You need that if you want to use zlib in your programs. Officially, zlib does not have a "programmers manual", but a quick read to zlib.h will make your ideas clearer.
  If you need a Visual Basic interface to zlib, see cmp-z-it.zip or http://www.dogma.net/markn/articles/zlibtool/zlibtool.htm and contrib/visual-basic.txt

zlib123dll.zip - pre-built zlib DLL, compiled with the Microsoft Visual studio 2003 compiler (the compiler is available as free download)

• This DLL is for Win32-x86. There is also a DLL for Windows 64 bits, for AMD64/Intel EM64T and for Intel Itanium.
  Make sure to define ZLIB_WINAPI before including zlib.h. Read contrib\vstudio\readme.txt file whithin zlib123.zip for more information.

zlib122asm_v1a.zip - Latest assembly code for zLib 1.22, both 32 bits (x86) and 64 bits (x86-64 for AMD64/Intel EM64T).

• This file contains latest optimized assembler code for Win32-x86 and Win32-x64 (64 bits for AMD64/Intel EM64T).
  It also contains a makefile for testzlib for Visual Studio 2005, for benchmarking and tests. You can also get 64 bits minigzip for x86-64 Windows, and both x86 and x64, with and without assembly code testzlib binary (or a more complete distribution) for doing benchmarks. I worked also on MD5 optimisation for AMD64.

Previous version (1.1.4):

zlib114.zip [146K] (or through FTP) - sources of zlib

• You need that if you want to use zlib in your programs. Officially, zlib does not have a "programmers manual", but a quick read to zlib.h will make your ideas clearer.
  NOTE: this archive is now THE SAME of the standard distribution.
  
  Take a look at the Users Corner.
  If you are going to rebuild the library by yourself, read the build instructions.
  If you need a Visual Basic interface to zlib, see cmp-z-it.zip or http://www.dogma.net/markn/articles/zlibtool/zlibtool.htm and contrib/visual-basic.txt

zlib114dll.zip [94K] - pre-built zlib DLL

• This DLL contains both Win16 and Win32-x86 versions.
  Make sure to define _WINDOWS and ZLIB_DLL before including zlib.h. You can get the additional build file (buildzlib114dll.zip) to recompile this DLL if you want.

资料来源：http://www.winimage.com/zLibDll/