In a new tutorial on the Zend Developer Zone, Sam reminds us that, sometimes, it's all about "Location, Location, Location" with Zend Framework applications.
I was having a conversation with a client recently on the topic of best practices. He asked me: "Where should I put the Zend Framework source code?" This is an excellent question that can not only be applied to Zend Framework, but to similar frameworks also. The question has in fact two answers in my opinion, which answer is right for you depends on how you answer this question.
He answers the question by asking a question of his own - is ZF part of your application or of your environment? There's (basically) two different paths to follow here and that question is the branching point. If its in the app, he recommends keeping it closely tied and in the "/library" of the app. If not, then it's recommended to place it out where multiple applications could get to it.
There's also third option, hybrid of the two that allows you to both keep the application split off on the backend but closely tied in deployment.