Derick Rethans is a PHP internals expert, author of Xdebug and an OpenStreetMap and mapping enthusiast. He has contributed in a number of ways to the PHP project, including the Xdebug debugging tool, and various extensions and additions. He’s a frequent lecturer at conferences, the author of php|architect’s Guide to Date and Time Programming, and the co-author of PHP 5 Power Programming. He is now working at MongoDB to work on the PHP driver for MongoDB.