A patch fixes #1391 "macruby interpreter quits on 'quit' out of scope" - http://www.macruby.org/trac/ticket/1391

id1391.patch

Changes in HEAD
	Modified lib/irb/context.rb
diff --git a/lib/irb/context.rb b/lib/irb/context.rb
index 0b03d00..a7e11fc 100644
--- a/lib/irb/context.rb
+++ b/lib/irb/context.rb
@@ -124,3 +124,7 @@ module IRB
     end
   end
 end
+
+def self.quit
+  exit
+end
	Modified lib/irb/source.rb
diff --git a/lib/irb/source.rb b/lib/irb/source.rb
index 03f7104..6324d15 100644
--- a/lib/irb/source.rb
+++ b/lib/irb/source.rb
@@ -170,14 +170,6 @@ module IRB
         super
       end
 
-      def on_ident(token) #:nodoc:
-        if @level == 0 && TERMINATE_KEYWORDS.include?(token)
-          @terminate = true
-        else
-          super
-        end
-      end
-      
       def on_lbrace(token) #:nodoc:
         @level += 1
         super

This is a quick patch. I think @alloy knows better fixing. However, this works.