wxrequire 'rubygems'
gem 'wxruby2-preview' # or the name of the gem you installed 
 require "wxruby" # wxruby 0.6.0
 # OR
 require "wx" # wxruby2
 include Wx 
 

 class MinimalApp < App
    def on_init
         Frame.new(nil, -1, "The Bare Minimum").show()
    end
 end
 

 MinimalApp.new.main_loop