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 works as an independent contractor and consultant on PHP extensions and related projects, including Xdebug.
This talk is for developers who want to know how to debug their code in a better way, through single step debugging, profiling, and simpler debugging tools.