The Zend Developer Zone has a new tutorial posted looking at PHP5 and the new XML tools that it has to offer - as broken up into categories:

• the DOM functionality (replacing DOM XML, ext/dom)
• SimpleXML
• XMLReader (replacing the ext/xml extension)
• XMLWriter
• XSL

Things are a bit different using XML in PHP 5. In a similar scenario, you could use one of the new native extensions, like DOM or SimpleXML, to manipulate the XML data tree. This tree can then be passed directly to and used by the XSL extension without incurring any additional overhead. There is no serialization nor copying involved; ext/xsl is able to work directly with the XML tree it is given, resulting in a significant improvement in use of system resources as compared to coding a similar task in PHP 4. So now that you have an idea why XML support got a face lift, you might like to know about the different tools available to you.

As mentioned briefly by Pierre-Alain Joye, the documentation (on the Livedocs website) has been updated for the XMLWriter package.

This is the XMLWriter extension. It wraps the libxml xmlWriter API.

This extension represents a writer that provides a non-cached, forward-only means of generating streams or files containing XML data. This extension can be used in an object oriented style or a procedural one. Every method documented describes the alternative procedural call.

The updated documentation cn be found here.

XMLWriter is finally bundled in php5. It will available and enabled by default in the next PHP release (5.1.2).

With XMLReader, XMLWriter is a really nice addition to the xml extensions.

The XMLWriter extension provides fast, non-cached, forward-only means of generating streams or files containing XML data.