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.
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.
Lightbox is small javascript library used to overlay images on top of the current page.
LiteSpeed is a high-scalability web server.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
Unpkg is a content delivery network for everything on npm.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.