Welcome to WebmasterWorld Guest from 220.127.116.11
Forum Moderators: httpwebwitch
the PECL WBXML module is a true module, written in C. I have a hunch that a WBXML conversion derived from PHP would be far less efficient than the module.
That said, I did a little more searching and haven't found anything like what you need. Keep looking... and maybe ask around in the PHP forum, the bona fide PHP experts hang around in there.