Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Moodle is a free and open-source Learning Management System (LMS) written in PHP and distributed under the GNU General Public License.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.