The jre/lib/rt.jar contains 3rdparty classes, specifically XML classes
from org.apache. This is a huge pain if one is trying to use a newer
version of the apache classes since there's no convenient way to put
them ahead of the rt.jar in the CLASSPATH. It seems that Javasoft
should either fully adopt the apache classes and move them into the
java.* or javax.* namespace or ship them in a separate jar (perhaps in
the ext/ directory) or just not ship them at all. As it stands,
software that I have that runs fine under 1.3 fails under 1.4.