title: Easiest way to add a GUI to C++ app
body: <p>I am producing a piece numerical software in C++ and want to add a GUI (mainly for Windows). I know how to produce GUIs using comfortable editors in modern languages like Java or .NET. Now my question is what is the <strong>easiest and most comfortable way to add a GUI frontend</strong> for my program. In the choice of the tools am completely free (open source and portability would be nice), but please also keep in mind how much boilerplate code and interfaces that have to be maintained are required if the GUI is implemented in another language (Like C#).</p>
  
  <p>Please don't suggest switching the whole project from C++! And note that the program does not require not much interaction between the C++ code and the GUI.</p>