The XSL Engine supports XSLT processing for drupal templates. Now you can leverage the power of XPATH/XSLT for traversing your data. Quickly and elegantly format your semantic data structures into custom HTML markup in no time.
PHP 5 and XSL.dll
Using native PHP support for XSLT it has low memory usage. This does create a dependency for DOMDocument and XSLTProcessor classes which can be found in the XSL.dll for PHP 5.
The other component to the engine is the module node_dto. This module handles the serialization of data objects such as your template variable structure into XML which in turn is sent to the XSLT processor for HTML formatting.
Two themes have already been developed using the XSL Engine and can be used for reference in creating new themes.
XSL Absolute is a zen liquid clone demonstrating the extensability of the XSL Engine, serves as a great base theme but not much glitter.
XSL Bartik is a Bartik clone. After seeing the new theme I really wanted it for drupal 6 so I reworked the templates for use with XSL Engine, XSL Bartik is a sub-theme of XSL Absolute, so you'll need to have both if you want to go with XSL Bartik.