http://www.microsoft.com/windows/ie/gzip.htm (PC Press Internet CD, 03/1996)GNU GZip Licensing Information
One component of Microsoft's VRML Add-In is the Free Software Foundation file known as “GZIP” in object code form. You can copy, redistribute, and modify GZIP under the terms of the GNU General Public License (either version 2 or later) as published by the Free Software Foundation. To find out about the license for GZIP, particularly with respect to information on offers to distribute the corresponding source code, visit the GNU website.