Perhaps a dumb Java Portable Launcher question, but...
Couldn't really find anywhere else for this, so put it up as a General Discussion.
To use OpenOffice Base OOo needs access to a java runtime.
The PA "Java Runtime" app takes care of downloading the necessary JREs. So long as the right default install folders are maintained, OpenOffice portable cleverly finds the necessary JREs. You just then need to confirm and away you go.
So, my question is simply, "what's the purpose of the Java Portable Launcher?"