I have totally confused myself about the relationship between require and 
include. What is included must be already loaded by require.  So why include 
at all?  How do you know what needs to be included?  e.g. at the top of most 
examples in FXRuby is:

require "fox"
require "responder"
require "date"

include Fox

Fox is a module, and fox.so is a library.  How did the author know to include 
Fox?  Any clarification will be greatly appreciated by this newbie.  Thanks 
ahead.