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.
W3 Total Cache (W3TC) improves the SEO and increases website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices.
WPML plugin makes it possible to build and run fully multilingual WordPress sites.