The replacement has a long history of successfully doing jobs you are not aware of and seems to have had almost zero impact on your life or the lives of anyone you know.

One thing is certain, all of these very important people make a lot more money than most of you and therefore you need to know all this so that you may display the appropriate deference on the extremely slim chance that you ever actually do meet any of these very important people.

The beatings will continue until morale improves. That is all.

Does XSL Leak File Handles?

No, but it may appear to in some use cases. If you use redirect:write a lot for example:

   <redirect:write file="{$outfile}">
   ...
   </redirect:write>

The solution here is to bracket the write with open and close so that the engine does not have to implicitly track the open file stream:

   <redirect:open file="{$outfile}"/>
   <redirect:write file="{$outfile}">
   ...
   </redirect:write>
   <redirect:close file="{$outfile}"/>

package demo;

import java.io.FileOutputStream;
import java.io.IOException;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;

public class HTMLDemo {

   public static void main(String[] args) {
      FileOutputStream outputStream = null;

      try {
         Document newDocument = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
         Element html = newDocument.createElement("html");
         Element head = newDocument.createElement("head");
         Element body = newDocument.createElement("body");

         Element p = newDocument.createElement("p");
         Text textNode = newDocument.createTextNode("Hello World");

         p.appendChild(textNode);
         body.appendChild(p);

         html.appendChild(head);
         html.appendChild(body);

         newDocument.appendChild(html);

         outputStream = new FileOutputStream("/demo.html");
         TransformerFactory.newInstance().newTransformer().transform(
               new DOMSource(newDocument), new StreamResult(outputStream));         

      } catch (Exception e) {
         e.printStackTrace();
      } finally {
         if (outputStream != null) {
            try {
               outputStream.close();
            } catch (IOException e) {
               e.printStackTrace();
            }
         }
      }
   }
}

I leave things like doctype as an exercise to the reader.