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.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
MkDocs is a static site generator, used for building project documentation.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
Unpkg is a content delivery network for everything on npm.