This is a no-brainer, really. From a security standpoint alone, PHP 5 is superior, but through in the OOP and there's no question. There are books written on the subject - do an amazon search. And don't forget eric's advice. mark >>> Paul Novitski <paul@xxxxxxxxxxxxxxxxxxx> 02-Feb-06 19:36 PM >>> At 04:09 PM 2/2/2006, Tim Burgan wrote: >I'm wondering if you can outline, or direct me to a resource that >explicitly notes the benefits of php5 over php4. They've got everything you need at php.net:* Appendix B. Migrating from PHP 4 to PHP 5 http://php.net/manual/en/migration5.php * to paraphrase Arlo Guthrie