Username or EmailPassword
Are you daft? (That was rhetorical, as anyone can plainly see the answer from your comment)
Like I said, Swing's performance and aesthetics are debatable.
It's design from a programmer's standpoint is superb. It is very cleanly designed and implemented.
Swing hasn't exploded on the desktop, but not because it's development framework is poor. It used to be slow, and currently still looks "not quite right."
However, it has not had any real competition in the Java space since it's inception until now. Once SWT started becoming popular, Sun has really put resources into making Swing work.
I just wish Sun would open source this stuff so real progress could be made.