Run the SL on your terminal.
$ gem install pebbles-sl
$ sl
in your terminal, or
require 'pebbles/sl'
Pebbles::SL.run
in your Ruby script
This package is based on the SL command by Masashi Toyoda, written in C language.
See http://www.tkl.iis.u-tokyo.ac.jp/~toyoda/index_e.html for details.