cdnjs is a free distributed JS library delivery service.
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.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.
Wistia is designed exclusively to serve companies using video on their websites for marketing, support, and sales.