And, arguably more important:
Note: This extension has been moved to the » PECL repository and is no longer bundled with PHP as of PHP 5.0.0.
Note: This extension is no longer marked experimental. It will, however, never be released with PHP 5, and will only be distributed with PHP 4. If you need DOM XML support with PHP 5 you can use the DOM extension. This domxml extension is not compatible with the DOM extension.