Hi Eric,

  The answer to your question I found the book "Programming Cocoa with Ruby" (Brian Marik) on the pages 98ff:

A method super_foo calls the method foo in the first Objective-C ancestor class.
The pseudomethod super calls the first Ruby ancestor.

myMini-2:rubycocoa-oddities kittekat$ more super-and-super.rb 
#---
# Excerpted from "RubyCocoa",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material, 
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose. 
# Visit http://www.pragmaticprogrammer.com/titles/bmrc for more book information.
#---
require 'osx/cocoa'

# This file shows that the RubyCocoa super_x way of calling a
# superclass method ONLY looks in an Objective-C object, not a
# superclass that's defined in Ruby.

class RubyFromObjC < OSX::NSObject
  def description
    "Some kind of RubyFromObjC"
  end
end

class RubyFromRuby < RubyFromObjC
  def description
    "super_description says: " + super_description +
      "\nbut super says: " + super + 
      "\nThe super_description comes from NSObject#description."
  end
end

if $0 == __FILE__
  puts RubyFromRuby.alloc.init.description
end
    
myMini-2:rubycocoa-oddities kittekat$ ruby super-and-super.rb 
super_description says: <RubyFromRuby: 0x1018f8ba0>
but super says: Some kind of RubyFromObjC
The super_description comes from NSObject#description.
myMini-2:rubycocoa-oddities kittekat$ 

Regards
Wolfgang