Standard libraries in JAXP?

[siegfried]

I can run the ApplyXPathDOM.java sample by making a class path of the jar files shipped (downloaded) with apache Xalan. Since these are now standard interfaces (and implementations), why cannot I abandon the jars in Xalan and just use the implementations in my 1.5 JRE? Can the ApplyXPathDOM.java run with just the classes in the Sun 1.5 JRE?   Thanks, Siegfried