The gzip Home Page.

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. It has been adopted by the GNU project and is now relatively popular on the Internet. gzip was written by Jean-loup Gailly (jloup@gzip.org), and Mark Adler for the decompression code.

By virtue of links, this seems to be the official home page.