Posted By: TimFPhusion Passenger can be run as a stand-alone server for Ruby. It does not require any other web server. You can start Phusion on the default HTTP port (but you must first stop the other web server that is listening on port 80) with 'sudo passenger start -p 80'
See the Phusion Passenger documentation for more details:http://www.modrails.com/documentation/Users%20guide%20Standalone.html
You can, however, also run it as a module for your web server if you like. The documentation for apache and nginx are herehttp://www.modrails.com/documentation/Users%20guide%20Apache.html
and here,http://www.modrails.com/documentation/Users%20guide%20Nginx.html