Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Firebase is a Google-backed application development software that enables developers to develop iOS, Android and Web apps.
Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
Unpkg is a content delivery network for everything on npm.