[Randy11]

@Sogaiu :

Roughly, with a Max2 I can forget to take my netbook every time. Yes, it can't replace a computer, but when the aim is to study a book like Effective testing with Rspec-3, small power is enough. My old netbook is a ASUS EEE PC 1001px with only 2 cores and 2 GB of RAM. With an external keyboard, for occasional and small tests it will be sufficient.

For the GUI, the package for Debian is 'ruby-tcltk', but the 'gem' exists too.

A small example from A First (Real) Example :

require 'tk'
require 'tkextlib/tile'

root = TkRoot.new {title "Feet to Meters"}
content = Tk::Tile::Frame.new(root) {padding "3 3 12 12"}.grid( :sticky => 'nsew')
TkGrid.columnconfigure root, 0, :weight => 1; TkGrid.rowconfigure root, 0, :weight => 1

$feet = TkVariable.new; $meters = TkVariable.new
f = Tk::Tile::Entry.new(content) {width 7; textvariable $feet}.grid( :column => 2, :row => 1, :sticky => 'we' )
Tk::Tile::Label.new(content) {textvariable $meters}.grid( :column => 2, :row => 2, :sticky => 'we');
Tk::Tile::Button.new(content) {text 'Calculate'; command {calculate}}.grid( :column => 3, :row => 3, :sticky => 'w')

Tk::Tile::Label.new(content) {text 'feet'}.grid( :column => 3, :row => 1, :sticky => 'w')
Tk::Tile::Label.new(content) {text 'is equivalent to'}.grid( :column => 1, :row => 2, :sticky => 'e')
Tk::Tile::Label.new(content) {text 'meters'}.grid( :column => 3, :row => 2, :sticky => 'w')

TkWinfo.children(content).each {|w| TkGrid.configure w, :padx => 5, :pady => 5}
f.focus
root.bind("Return") {calculate}

def calculate
  begin
     $meters.value = (0.3048*$feet*10000.0).round()/10000.0
  rescue
     $meters.value = ''
  end
end

Tk.mainloop