Nimbus provide more lively look and feel in Swing UI. Here are some examples:
Default Look And Feel(Click to see enlarged mode)
Nimbus Look And Feel((Click to see enlarged mode)
Since the image is little small and related to my Online Java Project(which I can't change), so I provide another example here from my last blog code.
Default Look And Feel
Nimbus Look And Feel
Something more interesting is focus traversal on components. For Default L&F, you can see that there is a dotted rectangle on Button 3, which says "Focus is here" whereas in Nimbus you can see Button 1 with little bluish highlight which says "Look at my focus" :)
Quickest way to try, command line:
Run my previous (or any UI code) with the following option:
java -Dswing.defaultlaf=com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel LayoutCheck
Off course, you can do it with code :
UIManager.setLookAndFeel(Use try, catch and respect Exception handling as well.