Apache HTTP Server, colloquially called Apache, is the world's most used web server software.

lighttpd (lighty) is an open-source web server optimized for speed-critical environments while remaining standards-compliant, secure and flexible.

Hiawatha is an advanced and secure web server for Unix.

Mongoose is an embedded web server.

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

Internet Information Services (IIS) is an extensible web server.

Caddy is an HTTP/2 web server with automatic HTTPS.