In the vein of some of Lorna's articles, this is more a note for myself than anything else. Not everything is explained in detail as it assumes you know how to use a command line...These are the steps I take to get the Apple supplied PHP working with GD, PDO_MySQL and Xdebug working on OS X 10.5.

He show how to: run Apache in 32 bit mode, download and install MySQL, setup and configure Apache, changes values in the php.ini and install the other extensions (like XDebug and the GD library). He uses the latest PHP 5 distribution at the time - PHP 5.2.6 - but these instructions should work for any in the PHP 5.x series you might want to use.