/usr/bin/java -Djava.class.path="$HOME/runescape/bin/jagexappletviewer.jar" -Dcom.jagex.config=http://www.runescape.com/k=3/l=en/jav_config.ws
jagexappletviewer user/runescape/images

it says that the class jagexappletviewer.jar cannot be found. its definately in there