Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.

WebSocket is a communication protocol that provides full-duplex communication channels over a single, long-lived connection, enabling interactive communication between web browsers and servers.

Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.

Varnish is a reverse caching proxy.