Amazon S3 or Amazon Simple Storage Service is a service offered by Amazon Web Services (AWS) that provides object storage through a web service interface.
cdnjs is a free distributed JS library delivery service.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
Sentry is an open-source platform for workflow productivity, aggregating errors from across the stack in real time.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.