Apache is a free and open-source cross-platform web server software.
Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
PHP is a general-purpose scripting language used for web development.
Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.
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.
Varnish is a reverse caching proxy.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.