Run your phpinfo() page (XAMPP)
A - I think what you want is already installed
B - you might just have uncomment the extension in php.ini (very likely)
-- look for the extension name, remove the semi-colon in front - save file
it might be:
extension="zziplib.so"(sorry no Mac here for test on)
http://www.apachefriends.org/en/xampp-macosx.html -
86 MB Apache 2.2.14, MySQL 5.1.44, PHP 5.3.1, Perl 5.10.1, ProFTPD 1.3.3, phpMyAdmin 3.2.4, OpenSSL 0.9.8k, GD 2.0.35, Freetype 2.3.5, libjpeg 6b, libpng 1.2.32, libungif-4.1.4, zlib 1.2.3, expat 2.0.1, Ming 0.4.2, Webalizer 2.01-10, pdf class 009e, mod_perl 2.0.4, SQLite 3.6.3, gdbm-1.8.3, libxml-2.7.2, libxslt-1.1.24, openldap-2.3.43, imap-2004g, gettext-0.16.1, libmcrypt-2.5.8, mhash-0.9.9,
zziplib-0.13.48, bzip2-1.0.5, freetds-0.64
MD5 checksum: fcbd4b14461a5b9e7a817f99defd0be2
That's a more recent release than what you quoted -
Good Luck