title: Is there an open-source tool for drawing OPC UA graphical notation?
body: <p>Do you know about some drawing tool that supports the <strong>Graphical Notation</strong> described in the OPC UA standard Part 3 Annex D?</p>
  
  <p>The notation is similar to UML but has some extra elements that map nicely to the OPC UA information model (like different types of references). This is an example of the notation:</p>
  
  <p><a href="https://i.stack.imgur.com/tMgOg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tMgOg.png" alt="An example of the notation"></a></p>
  
  <p>It would be great if it was free, ideally open-source. Thanks.</p>