You’ve seen it before, but never with quite so many shoes: a Ruby adaptation of the venerable Logo turtle, complete with color scheme and crude triangular testudine.
You can make fun things, like a spiral of squares:
def square size
repeat 4 do
move size
right 90
end
end
@x = 1
repeat 90 do
square @x += 1
right 4
end

Hrm. Seems to act a bit funny on Linux. For every key I type into each of the text boxes a dialog pops up with the keystroke and I have to click okay.