zlib is designed to be a free, general-purpose, legally unencumbered — that is, not covered by any patents — lossless data-compression library for use on virtually any computer hardware and operating system.
|-- The zlib web site http://www.zlib.net/|
This library is almost certain to be installed on your system. If it isn’t or you don’t want to use the default library you can download it from http://www.zlib.net/.
The zlib sources are downloaded from https://anonsvn.wireshark.org/wireshark-win32-libs/trunk/packages/ and compiled locally.