Zope is written in Python and is a collection of tools that allow for the creation and presentation of websites. It would be like a web-based PHP IDE where developers would work together via the web, in the back room of a central site, to build the pieces used to present that production web site.
Zope has an engine that produces HTML pages from the pieces inside its database. It can prepare and deliver web pages itself and be the only web server. Alternatively, it can operate in conjunction with Apache where some URLs are handled by Apache and other URLs are handled by Zope.
I used Zope on my campaign website at http://www.lynosullivan.org/ if you are interested in seeing a Zope site in operation.
Python is a scripting language with the functionality of Perl. It is a programming language that can generate HTML text to be passed to the HTTP server. I like the syntax of Python better than Perl.
I am currently learning PHP instead of using Zope because I am working on a site that does not host the Zope engine. Also, I want to be able to share my work and believe it would be next to impossible to effectively share the myriad of pieces inside a Zope database whereas it is a simple matter to share a complete PHP application--because Zope is a myriad of pieces, anyone wanting to use my pieces would have to follow a very intricate, by hand, installation process to put all the pieces into their appropriate place inside Zope.
I started learning PHP instead of Python because of PHP's web centricity. I am currently reconsidering that decision because I am finding it a pain to deliver a 1st class GUI type client application using HTML and server-side PHP. I have played with Javascript for the client side pieces. I also played with Java but found the learning curve to be too steep.
Also, to be perfectly honest, I do not understand the relationship between Zend and PHP. I do not want to make any choices that might lock me and the people with whom I share code into proprietary solutions. Python is completely open sourced and will always remain so but I am not so sure about PHP, for the long haul.
I am still trying to decide what to do. I hope this information helps.