I just got Merb running under Phusion Passenger on my OS X Leopard MacBook and it all went well but with a couple gotchas. I looked at Manfred’s and TopFunky’s notes, but I couldn’t get Merb to kick in.
It turns out I was missing a config.ru as they were running straight Rails apps and Merb has to (gets to?) run as a Rack app. This page on Merbivore has all the info. I was being a bit dense about actually taking that first bit of code (# config.ru, etc) and putting it into a file at the root of my Merb app named config.ru. Once done Merb fired right up and it’s working swimmingly.
mac merb rubyNo tags

Sebastian · August 9, 2008 at 1:03 pm
There is Phusion Passenger for rails?
Admin comment by Tom · August 10, 2008 at 6:12 am
That’s primarily what Passenger is targeted towards. See the web site.
Nick · March 12, 2010 at 12:51 pm
This is the new home http://wiki.merbivore.com/deployment/passenger