title: How to create a Sitecore ribbon button with dropdown menu?
body: <p>The Sitecore PageEditor and Preview interfaces feature a language selector button that triggers a "dropdown"/overlay menu where the user can select a language. How do I replicate this behavior?</p>
  
  <p>(I set out to answer this question, and came up with a solution. Posting to SOF for comment/enhancement.)</p>