Zack, Here are the main differencies between ASPRunnerPro and PHPRunner.
ASPRunnerPro generates ASP pages that work on Windows-based Web server. PHPRunner generates PHP pages which means you can use it on both Windows and Unix Web servers. Usually Windows guys use ASP, while Unix guys use PHP.
PHPRunner currently supports MySQL database only. ASPRunnerPro supports virtually every ODBC compliant database.
ASPRunnerPro comes with Template Editor which makes template customization easier. This is it.