RTrans is a library for internationalizing applications written in Ruby, 
much they way gettext does, but gettext is written in C and the 
translation files require compilation before they can be loaded into the 
application.

RTrans on the other hand is 100% pure ruby, reads translation strings 
directly from text, updates them when unknown strings are issued, and 
automaticly reloads them if the translation file was changed.

RTrans can be downloaded from:

http://idanso.dyndns.org/radical/Download

 From the README file:
=====================

RTrans is a pure ruby library for internationalizing(I8N) applications, it
uses pure text(unlike gettext), and the I8N can be updated on-the-fly.

The library code was extraced from the Radical application server, as I
believe it is useful in other Ruby applications as well:

http://idanso.dyndns.org/radical/

The code is copyrighted by Idan Sofer <idan / idanso.dyndns.org>, and licenced
under the terms of the GPL V2.

an example application:

$lang="en"
require 'translate'
Intl=Radical::Translations::TranslationLoader.new './intl'

def intl(str)
  Intl[$lang,"MyApp"][str]
end

puts intl 'Hello World. How are you doing?'