I ignored the requirements page entirely, downloaded it as a zip file into my existing (PHP-based) web server, unzipped it, and it basically worked immediately.

I ignored the requirements page entirely, downloaded it as a zip file into my existing (PHP-based) web server, unzipped it, and it basically worked immediately. I think this would be the case for anyone else running a relatively modern existing PHP setup, and for everyone else they can just use the Docker image.