The launcher sets sun.desktop to either windows or gnome.
It may once have been used to have it be motif on Solaris systems
as it is read by Swing's UIManager to choose the system L&F
I expect we can select defaults for each platform now
and leave sun.desktop as an option to be set by the application
and read by this same code. Or just remove it completely
from Swing as well as the launcher.
Here are the usage sites, the first of which is J2DBench !?
0 XMLHTMLReporter.java 1226 buffer.append("<tr><td
                             bgcolor=\"#f0f0f0\">sun.desktop</td><td>" +
1 XMLHTMLReporter.java 1227 sysProps.get("sun.desktop") + "</td></tr>");
2 System.c 366 PUTPROP(props, "sun.desktop", sprops->desktop);
3 UIManager.java 660 String desktop = AccessController.doPrivileged(new
                             GetPropertyAction("sun.desktop"));
4 SynthLookAndFeel.java 807 AccessController.doPrivileged(new
                             GetPropertyAction("sun.desktop"));