Gunicorn is described as ''Green Unicorn' is a Python WSGI HTTP Server for UNIX. It's a pre-fork worker model ported from Ruby's Unicorn project. The Gunicorn server is broadly compatible with various web frameworks, simply implemented, light on server resource usage, and fairly' and is a Web Server in the development category. There are more than 25 alternatives to Gunicorn for a variety of platforms, including Linux, Windows, Mac, Self-Hosted and BSD apps. The best Gunicorn alternative is nginx, which is both free and Open Source. Other great apps like Gunicorn are Apache HTTP Server, Caddy, Ferron and lighttpd.