A debugger is one of the most powerful development tools available. However, with PHP, debugging a site can be tricky. A lot of times, the host you need to debug is remote. Xdebug, the PHP debugger, solves this problem with their remote debugging feature.
Unfortunately, getting remote debugging with xdebug setup on Mac OS X can be a little tricky. This tutorial will help you setup your environment for easy remote debugging using Xdebug and MacGDBp.