I'm a third of the way through the Zope Book and understand the difference as it is written. As you can appreciate, in learning a new technology, what is missing is the experience that would guide your focus. What I would like is an idea of how real world developers use these in the following senses. Do you use one exclusively (in conjunction with Python)? Do you use primarily one or the other? Do you use both roughly equally? Are there classes of applications where you have found one is preferred? Your advice would be welcome.