Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
Mapbox.js is a JavaScript library provided by Mapbox for working with interactive maps and geospatial data.
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.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
A modest JavaScript framework for the HTML you already have.
Unpkg is a content delivery network for everything on npm.