Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
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.
OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.
RackCache is a quick drop-in component to enable HTTP caching for Rack-based applications.
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.