title: Why aspnet_isapi.dll still exists in iis7?
body: <p>As far as i know asp.net has been integrated with IIS.</p>
  
  <p>That is to say, asp.net runtime is always hosted in IIS7 no matter the incoming request is.
  ie. An <code>.aspx</code> request or others static files request like <code>.html</code> or <code>.jpg</code>.</p>
  
  <p>We know that in IIS6, <code>aspnet_isapi.dll</code> will be loaded to create asp.net runtime and run asp.net only when requests such as <code>.aspx</code>,<code>.ashx</code> arrive.</p>
  
  <p>Now that asp.net has been integrated with IIS7 in "Integrated Mode" what's the usage of <code>aspnet_isapi.dll</code>? Is it the reason why we can still see aspnet_isapi.dll in iis7 is compatibility ?</p>