Question over NumberFormatException

[Jeena Jeen]

In Chapter 5 of K&B Java 5 (Page 370) its mentioned that NumberFormatException is Programmatically thrown Exception.
But if I see this in java spec then it extends from IllegalArgumentException which extends from RuntimeException .
So this should be a JVM exception rather than programmatically thrown Exception.
Same is the case of IllegalArgumentException.
Doesn't programmtically thrown Exception means Checked/compileTime Exception? Or may be I am mixing up these two things?

[Eugene Rabii]

Something really nice I have seen from a Senior from SUN : (!checkedException)!=unchekedException...