title: What is the difference between a COM Add in and a VSTO Add in
body: <p>I am trying to develop an addin for outlook, and I found a provider <a href="http://www.add-in-express.com">http://www.add-in-express.com</a>. But, they have 2 offerings in one(http://www.add-in-express.com/add-in-net/index.php) they allow to create COM add in Using VS 2010 and .Net Framework 4.0 (How is that possible, I always thought COM can only be create in VB6, else You have to create a COM callable Wrapper (CCW)).</p>
  
  <p>The other offering is VSTO Tools (http://www.add-in-express.com/add-in-vsto/index.php), Which is also using .Net Framework 4.0 and this is totally confusing. </p>
  
  <p>Please help me understand.</p>
  
  <p>Regards
  Mohit Thakral</p>