Drupal is a free and open-source web content management framework.
Internet Information Services (IIS) is an extensible web server software created by Microsoft for use with the Windows NT family.
PHP is a general-purpose scripting language used for web development.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.