NGINX

NGINX is an open-source web server that also functions as a reverse proxy, load balancer, and HTTP cache. It was built to solve the C10k problem — handling tens of thousands of concurrent connections efficiently — using an asynchronous, event-driven architecture instead of the thread-per-connection model older web servers relied on. This makes it exceptionally fast and memory-efficient under load.

In a self-hosted deployment, NGINX typically sits in front of an application (running in Docker or on bare metal) and terminates TLS, routes requests based on hostname or path, and serves static assets directly. Combined with Certbot, it can automate Let's Encrypt certificate issuance and renewal, though this requires separate configuration — unlike Caddy or Traefik, NGINX does not handle automatic HTTPS out of the box.

NGINX is distributed as free, open-source software (nginx.org), packaged for every major Linux distribution and as an official Docker image. F5's commercial NGINX Plus and NGINX One tiers add active health checks, dynamic reconfiguration via API, session persistence, and enterprise support, but the open-source core is what almost all self-hosted stacks in the wild actually run. Configuration is declarative, text-based, and extremely mature — decades of documentation, tutorials, and Stack Overflow answers exist for nearly any routing scenario.