You can download the latest version of XOOPS, as well as read more about this package, at www.xoops.org. PHPNuke is at www.phpnuke.org, and PostNuke is at www.postnuke.org. The WeBLog module for XOOPS is availab le from www.wellwine.net.
PHP is available at www.php.net, and MySQL is at www.mysql.com. Many modern Linux distributions and nearl y all hosting providers come with PHP and MySQL already, so you probably do not need to install them.