title: TamperMonkey - message between scripts on different subdomains
body: <p>I have two scripts. Each runs on a different subdomain of our company <code>"Example.com".</code></p>
  
  <pre><code>Script #1 -- house.example.com
  Script #2 -- bob.fred.example.com
  </code></pre>
  
  <p>Same domain, different subdomains.</p>
  
  <p>When a particular element appears on <code>house.example.com</code>, I need to send a message over to the script running on <code>bob.fred.example.com</code></p>
  
  <p>Since Google extensions can exchange messages between extensions, there must be a way with TamperMonkey to exchange messages within the same extension, between scripts -- especially if they run on the same second-level domain.</p>
  
  <p>Can anyone point me in the right direction? An example or two would be worth their weight in gold.</p>
  
  <hr>
  
  <p><strong>Update:</strong> Although Gothdo referenced <a href="https://stackoverflow.com/questions/4079280/javascript-communication-between-browser-tabs-windows">Javascript communication between browser tabs/windows</a> as containing an answer to this question, he failed to take into consideration the cross-origin policies involved. <strong><em>None of the answers in that referenced question provide a clear answer for cross-origin browser tab communications, which was the main point of this question.</em></strong> I have now researched and solved this problem, getting ideas from a number of SO and non-SO sources. If this question is re-opened, I will post my solution.</p>