AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
RackCache is a quick drop-in component to enable HTTP caching for Rack-based applications.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.