title: Matplotlib: Markers surrounded by white space
body: <p>This is a plot from a <a href="http://www2009.org/proceedings/pdf/p801.pdf" rel="nofollow noreferrer">2009 paper (PDF)</a>.</p>
  
  <p><img src="https://i.stack.imgur.com/QqCej.png" alt="Plot from "></p>
  
  <ul>
  <li>What software was used to draw this?</li>
  <li>How can I achieve the same type of drawing the markers surrounded by white space with matplotlib?</li>
  </ul>