From: "Bartosz Dziewoński" <matma.rex@...>
Date: 2012-03-13T22:13:33+09:00
Subject: Re: arcadia IDE requires tcl/tk and ruby-tk

Quick googling found this: http://ruby.about.com/od/tk/a/Tk.htm

This command should be all you need. (I didn't try it, I don't have
access to an Ubuntu computer right now.)

$ sudo apt-get install libtcltk-ruby

-- Matma Rex