Ruby breakfast

I was trying to remove the following warning from passenger-memory-stats, I had to install apache2 but without running it :
*** WARNING: The Apache executable cannot be found.
Please set the APXS2 environment variable to your ‘apxs2′ executable’s filename,
or set the HTTPD environment variable to your ‘httpd’ or ‘apache2′ executable’s filename.
Solution (found here) :

So you’ve got a fresh new Rails app to deploy and you’re wondering which Ruby app server to use.
The old school way : a bunch of single process workers monitored (by Monit or God) and reverse proxied by (usually) Nginx. A little old-fashioned because it needs a serious monitoring configuration in order to deal with [...]