Apache is a free and open-source cross-platform web server software.
PHP is a general-purpose scripting language used for web development.
Pingdom RUM(Real User Monitoring) is a feature of the Pingdom website monitoring and performance testing service. RUM enables you to collect and analyse data on how real users are experiencing your website.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.