Apache is a free and open-source cross-platform web server software.
Drupal is a free and open-source web content management framework.
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.
Matter.js is a 2D physics engine for the web. It provides JavaScript-based tools for simulating rigid body physics in 2D environments.
Open Graph is a protocol that is used to integrate any web page into the social graph.
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.