I could not help but notice that all DOM XML calls use an
underscore-based convention:

i.e.
$mynode->append_child($achild);

I am no language lawyer but if you read the DOM Core documentation
(http://www.w3.org/TR/DOM-Level-3-Core/core.html) it suggests a case-based (no underscore) convention:

i.e.
$mynode->appendChild($achild);

Also, every DOM compliant library that I've looked at uses this same convention.  Will the case-based convention be used in PHP 4.3.0?  If not then it should be considered as it seems to be a violation of the DOM.

Warm regards,

Brent