Swing is standard GUI for Java (in spite of many seeing the future in JavaFX). What do you think, is Swing following the MVC paradigm or not? Recently Swing and JavaFX interoperability has been greatly improved.
Listen to podcast #2: to learn about our take on Swing and its poor reentrancy. Find out what it may mean for your own API design and especially Runtime_Aspects_of_APIs that you create. Learn to fight with that problem by maximizing the declarative nature of your API.