cdnjs is a free distributed JS library delivery service.
Cloudflare Browser Insights is a tool that measures the performance of websites from the perspective of users.
Express is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs.
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.
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.