Back when Java had just introduced Swing to supplement/complement AWT, I remember you had a set of components (that you could even style in different ways with themes), a fairly object-oriented approach, and with the open-source MiG layout manager (that still exists today) a powerful way of laying out forms with constraints to adapt to changing screen/window/font sizes. I feel like UI framework progress from Windows 3.1 to Swing+MiG was much greater than anything I've seen since.