cdnjs is a free distributed JS library delivery service.
Chart.js is an open-source JavaScript library that allows you to draw different types of charts by using the HTML5 canvas element.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.