eZ Publish is a PHP based CMF/CMS for publishing, especially editorial content.
eZ Publish is a PHP based CMS. Someone calls it a CMF where F stands for framework. It's very flexible: it has a pool of basic classes from where you can choose to create your content (such as Folder, Article, Link, File and so on), but it allows you to add or to modify classes, adding other attributes to them.
One of its greatest features is the cache handling, very powerful since the focus of eZ Systems (the company behind eZ Publish) is on the editorial world and large size sites.
There is a kernel, where the core functionality is kept, and an extension section where you can add your own modules (as extensions are called in eZ Publish).
It supports workflows, notifications and has a built in e-commerce system with lots of features.
As for the front end part, the HTML is integrated with a templating language that closely resembles PHP, but it has less functionality.
Beware, though: there is just enough documentation for the templating system, the documentation for the PHP part is really scarce. The main source of information is the forum, but don't expect too much. Most of the time, you have to extract information and solutions from other people's code.
It has also an extensions repository where you can search for tools and extensions that easy your work. There are some great extensions, like sqliimport
for importing data.
From version 5, eZ Publish is based on Symfony 2 framework.