AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Apache is a free and open-source cross-platform web server software.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
PHP is a general-purpose scripting language used for web development.
Unpkg is a content delivery network for everything on npm.