Apache is a free and open-source cross-platform web server software.
CentOS is a Linux distribution that provides a free, community-supported computing platform functionally compatible with its upstream source, Red Hat Enterprise Linux (RHEL).
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
PHP is a general-purpose scripting language used for web development.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.