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 Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
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.
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.