XSLT syntax highlighting

No, it is quite easy to make it work with saxon 8 (actually it was originally writen for saxon8 and xalan and later backported to saxon6):

1) You need ConnectorSaxon8.java:

package net.sf.xslthl;

import java.io.*;
import java.util.*;
import javax.xml.parsers.*;
import org.w3c.dom.*;

public class ConnectorSaxon8 {

private static Node blockToDomNode(Block b, Document doc, Config config) {
Node textNode = doc.createTextNode(b.getText());
if (b.isStyled()) {
Element elem = doc.createElementNS(config.uri, config.prefix + ":" + ((StyledBlock)b).getStyle());
elem.appendChild(textNode);
return elem;
}
return textNode;
}

protected static NodeList highlight(String source, MainHighlighter hl, Config config) throws Exception {
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = dbf.newDocumentBuilder();
Document doc = builder.newDocument();
Element fragment = doc.createElement("container");
doc.appendChild(fragment);

List<Block> l = hl.highlight(source);
for (Block b : l) {
fragment.appendChild(blockToDomNode(b, doc, config));
}

return fragment.getChildNodes();
}

public static NodeList highlight(String hlCode, String source) throws Exception {
try {
Config c = Config.getInstance();
MainHighlighter hl = c.getMainHighlighter(hlCode);
return highlight(source, hl, c);
}
catch (Exception e) {
e.printStackTrace();
return null;
}
}

}

2) compile it with saxon8.jar on path

3) In output_html.xsl you have to replace all lines like this one:
<xsl:variable name='pass1' select="hl:highlight('java', $source)" />
with:
<xsl:variable name='pass1'>
<xsl:copy-of select="hl:highlight('java', $source)" />
</xsl:variable>

4) running it like
java -cp ..\saxon8\saxon8.jar;..\saxon8\saxon8-dom.jar;classes net.sf.saxon.Transform -o example-java-to-html.html "example_sources/example-java.xml" xsl/example-java-to-html.xsl

(note that you must have there also saxon8-dom.jar, not just saxon8.jar)