Any reason that the Level 2 interfaces have the EXACT SAME NAME a s the Level 1 interfaces?

This makes it extremely hard to write Java code that:

a) Allows users to link in their own XML parser that implements org.w3c.*

and 

b) Mixes Level 1 and Level 2 XML parsers in the same VM.

Yes, I know about DOMImplementation.supports, but I am sorry, this is a
hack. I strongly suggest you hoist the new Level 2 methods into new
interrfaces that extend the Level 1 versions. This could be done as simply
as spawning off another package name, as follows:

// note package name
package org.w3c.dom.level2;

public interface Attr 
        extends org.w3c.dom.level2.Node, org.w3c.dom.Attr
{
    public org.w3c.dom.level2.Element getOwnerElement();
}



This allows me to do the more Java-esque test for extended functionality:

public void f(org.w3c.dom.Attr attr)
{
    if (attr instanceof org.w3c.dom.level2.Attr) {
  // use level 2 functionality here
    }
    else
    {
   // fall back on Level 1 functionality here
    }
}

For someone implementing a Level 2 parser, one can simply ignore the level 1
names as folows:

import org.w3c.dom.level2.Element;
public class MyElement implements Element
{
// implement union of Level 1 and Level 2 methods
}


I really really feel this is an important issue. I have personally written
code that loads multiple XML parsers and in the face of Level 1 and Level 2
parsers, I see trouble. It is also not that far fetched to come up with
scenarios where this can happen (a web server that loads independently
developed servlets that each use a different XML parser).

Thanks,
DB