title: What is a .NET application domain?
body: <p>In particular, what are the implications of running code in two different application domains? </p>
  
  <p>How is data normally passed across the application domain boundary? Is it the same as passing data across the process boundary? I'm curious to know more about this abstraction and what it is useful for.</p>
  
  <p><strong>EDIT:</strong> Good existing coverage of the AppDomain class in general at <a href="https://stackoverflow.com/questions/622516/i-dont-understand-appdomains">I don&#39;t understand Application Domains</a></p>