I was searching for XML handling and speed, memory factor on php. Particularly I was looking for how to use XSL transformations in php, do I need to populate exact xml or may I populate very large xml file and use the part htat I needed throught XSL. I came across with this article Processing Large XML Documents with PHP 5 which has benchmark for accessign particular record in XML using different feautures of PHP 5. Also there is very useful presentation explaining XML usage in PHP5, “XML in PHP 5” workshop slides.
Also there is a benchmark of XML parsers.