Ruby embeded getting the lightest

[Une bévue]

i've embeded Ruby in a MacOS X app (Address Book to html) with some
dependencies :
require 'osx/aeosa'
require 'iconv'
require 'xml/smart'
require 'xml/xslt'

the lib/ directory takes roughly 11 Mb and below that lib/ruby/1.8/
takes 6.5 Mb.

i'd like having my app the lightest as possible what part of the latest
could i suppress ?

for example, i don't use irb at all, could i suppress it ?

the same applies to rdoc, rss, runit, soap, webrick etc ...