cdnjs is a free distributed JS library delivery service.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Google Analytics is a free web analytics service that tracks and reports website traffic.
Linkedin Ads is a paid marketing tool that offers access to Linkedin social networks through various sponsored posts and other methods.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PHP is a general-purpose scripting language used for web development.
Recurly provides enterprise-class subscription billing and recurring payment management for thousands of businesses worldwide.
Stripe offers online payment processing for internet businesses as well as fraud prevention, invoicing and subscription management.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.