title: IXSomething vs ISomething
body: <p>I stumbled upon a documentation where COM objects have two kinds of interfaces, one starting with <code>I</code>, second with <code>IX</code>. Documentation says that <code>IX</code> is derived from <code>IUnknown</code>, and <code>I</code> is derived from <code>IDispatch</code>.</p>
  
  <p>Is it better to use <code>IX</code> interfaces if I use C++? As far as I understand the <code>I</code> interfaces are designed for scripting languages in this case? Are there any other differences?</p>