New on DZone.com's Web Builder Zone, there's an article from Giorgio Sironi comparing Struts to the Zend Framework (Struts, of course, being a standard Java MVC framework that's quite popular in that community).

This article is intended to be useful for who experiences a transition between Java and PHP, but also to learn what could be imported in a framework from the other. Keep in mind that in the PHP world using a framework is probably still not considered the default option (going with or without frameworks is a choice which is out of the scope of what I want to discuss today instead.) Let's see what surprises you when jumping from Zend Framework to Struts, or the other way around.

He compares them against each other mentioning things like the single servelet vs front controller idea, action classes vs action controllers, persistence, JSP vs embedded PHP and tag libraries vs view helpers.