Dave Thomas and Andy Hunt explore XML, noting that "Now we've gotten to the point where XML has become so obscure and so complex to write, that it can no longer be written by people... It's not designed for human consumption."
"The XMLEditorKit is a [commercial] 'Swing' XML Text component extension to the Sun Microsystems J2SE JFC/Swing 'javax.swing.text' package. It uses the Apache Xerces2 Java Parser 2.4.0, as its defaultXML Parsing and processing engine."