Here are screen shots from two identical java applications. The first one was built on OS 9.1 using CodeWarrior 5. The second one was built with Project Builder on Mac OS X (10.0.3). They are using the Swing libraries. It is an application similar to the hand held game Lights Out! The OS X version still has some quirks. When you move the mouse over the buttons you can see them flicker as they redraw.
Mac OS 9.1 with CodeWarrior 5	Mac OS X with Project Builder