title: Several VSTO Projects in same Solution
body: <p>What are the options if I want to deploy add-ins for various Office Apps?
  Can my <code>Solution</code> contain several VSTO <code>Projects</code>? For example one Excel AddIn, one Word AddIn, and one PowerPoint AddIn.</p>
  
  <p>Should I have/need each AddIn in a separate <code>Solution</code>? In particular if I run Excel, and later run Word without closing Excel: do I end up with two distinct instances running in parallel?</p>
  
  <p>Some of my classes are used by several AddIns, so it is more convenient to have everything in one <code>Solution</code>. That would also make deployment and updates easier. However I could always export the classes in a standalone DLL <code>Project</code> and reference that DLL in each <code>Solution</code>.</p>