Apache is a free and open-source cross-platform web server software.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
PHP is a general-purpose scripting language used for web development.
Unix is a family of multitasking, multiuser computer operating systems.
Unpkg is a content delivery network for everything on npm.
WhatsApp Business is a free to download app available on Android and iPhone using which businesses can connect with their customers.