cdnjs is a free distributed JS library delivery service.
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.
HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Pingdom RUM(Real User Monitoring) is a feature of the Pingdom website monitoring and performance testing service. RUM enables you to collect and analyse data on how real users are experiencing your website.
Varnish is a reverse caching proxy.