title: Mono for iOS/Android Open or Closed? Paid or Free?
body: <p>I am attempting to learn more about mobile/tablet development and, as a .NET developer, I am naturally drawn to Mono.  But I am confused--I thought that Mono was free and open source; however, all signs seem to point to Mono being a "pay-to-play" deal (https://store.xamarin.com/).</p>
  
  <p>Can someone please help me understand which is the correct answer?</p>
  
  <p>Thanks!</p>
  
  <p>Matt</p>