Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Prototype is a JavaScript Framework that aims to ease development of web applications.
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.