Nicholas Van Weerdenburg wrote:
> I've been wondering about why are irb and ruby separate programs.
> 
> Python combines the two concepts in its main executable, and I was
> wondering if there was a benefit to separating them.
> 
> Thanks,
> Nick

They are not. irb is a ruby program. Here's the content of 
/usr/local/bin/irb:

#!/usr/local/bin/ruby
#
#   irb.rb - intaractive ruby
#       $Release Version: 0.7.3 $
#       $Revision: 1.2 $
#       $Date: 2002/11/19 02:00:18 $
#       by Keiju ISHITSUKA(keiju / ishitsuka.com)
#

require "irb"

if __FILE__ == $0
   IRB.start(__FILE__)
else
   # check -e option
   if /^-e$/ =~ $0
     IRB.start(__FILE__)
   else
     IRB.setup(__FILE__)
   end
end

Gennady.