- PHP's XSL extension
- Drupal's Views module
- PHPMailer is a third-party library used by SunMailer to send emails. Many Linux distributions provide it through a package. If not, you can download it at http://phpmailer.worxware.com. Download the regular version, not an alternate version such as PHPMailer-FE. Extract the code to a reasonable location onto your server (e.g.: Ubuntu's libphp-phpmailer package puts the code in /usr/share/php/libphp-phpmailer). If you can only access your Drupal installation and not the entire server, put the code somewhere in the sites folder of your Drupal installation.