I gave it a try just now since you mentioned it, by doing the following:
And then to execute:
sudo aptitude install git-core rubygems
git clone git://github.com/adamwiggins/rush.git
I haven't learnt ruby yet, so all of my initial tries gave errors The examples on the homepage worked though. A bit different way of doing things than sh/bash, that's for sure.
$ exec rush/bin/rush
Exception NameError -> undefined local variable or method `ls' for localhost:Rush::Box