title: Emacs GUI for Mac, linux and windows
body: <p>I'd like to start using emacs but I want also a GUI in which it will be available in windows, ubuntu linux (desktop) and  mac osx. Is GNU/Emacs capable for this? What other choices are there and how different is for each OS?</p>
  
  <p>Also is there any disadvantages of using emacs with gui (for example, I can't use some kind of widgets or use something else) and how most other programmers prefer to use emacs? I want to use it as a replacement for textmate for ruby on rails development, any other suggestions? </p>