Sprockets makes it really damn easy in a few lines of ruby to concatenate and serve your coffee script files. It supports multiple template engines ERB, JavaScript, CSS, SCSS, etc you can even add a dash of ERB <%= %> to your coffeescript source files by naming your file source.coffee.erb and sprockets will automagically compile it down with ERB then CoffeeScript and concatenate it with other dependencies!
For the project I was working on I couldn't depend on Node.js for dependency management since I was creating a front-end browser game. At first I decided to implement my own hacked up solution in Ruby to substitute and concatenate coffee script source files... it wasn't pretty :( After moving to sprockets I was able to refactor a few hundred lines into three :)
For example, suppose you have a file that contains sprockets `require` syntax called Main.coffee
#= require "src/one"
#= require "src/two"
#= require "src/three"
MyApp ?= {}
Then all you need to do is create a Sprockets::Environment instance and add the source path
require 'sprockets'
env = Sprockets::Environment.new
env.paths << "src/coffee"
open("example.js", "w").write( env["Main.coffee"] )
Tada! It just works :)