ftp://alpha.gnu.org/gnu/gzip/

  The OpenPKG tarball "gzip-1.3.6-openpkg.tar" is just an unpacked GNU
  gzip 1.3.6 tarball "gzip-1.3.6.tar.gz" with the OpenPKG patch set
  ("gzip-1.3.6.patch") applied. The reason is two-fold: the OpenPKG
  bootstrap package ("openpkg") requires a simple distribution tarball
  (.tar) which is not already gzip'ed itself (.tar.gz) and which has
  security patches already applied (as unpacking of the GNU patch
  tarball required GNU gzip and hence we have to resolve this "chicken
  and egg" problem).

  $ gunzip <gzip-1.3.6.tar.gz | tar xvf -
  $ ( cd gzip-1.3.6; $ patch -p0 -b <../gzip-1.3.6.patch )
  $ tar cvf gzip-1.3.6-openpkg.tar gzip-1.3.6
  $ rm -rf gzip-1.3.6