cdnjs is a free distributed JS library delivery service.
Elfsight is an all-in-one platform offering 70+ customisable widgets for websites.
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.
Hugo is an open-source static site generator written in Go.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Typekit is an online service which offers a subscription library of fonts.