The Green Unicorn is a Python WSGI HTTP Server for UNIX. It uses 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 resources, and fairly speedy.

The debops.gunicorn Ansible role uses the Debian package configuration structure on older Debian and Ubuntu releases to manage multiple gunicorn applications as a single service. This can be used to deploy applications that use either a system Python installation, or a virtualenv Python environment.

From Debian Stretch upwards, the role configures a custom set of systemd units to support Green Unicorn service instances.