Apache is a free and open-source cross-platform web server software.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.
Unpkg is a content delivery network for everything on npm.