Deno

Apache Traffic Server is an open-source caching proxy server. It offers high-performance caching, proxying, and load balancing capabilities for web traffic management.

TwistedWeb is part of the Twisted framework, providing tools for building event-driven networking applications in Python. It's used for creating scalable web servers and services.

Caddy is a modern, Go-based web server known for its simplicity and automatic HTTPS features. It's designed to be easy to use and secure out of the box.

Centminmod is a shell script installer for quickly setting up a high-performance Nginx, PHP, MariaDB, and WordPress stack on CentOS systems.

Google Web Server (GWS) is Google's custom web server software. While not publicly available, it's optimized for Google's specific needs and high-traffic requirements.