A different kind of application server
Zope (Z Object Publishing Environment) is an open source application server written in Python that proposes a web development model radically different from those based on CGI or Java servlets. Instead of mapping URLs to scripts or classes via external configuration, Zope uses URL traversal: each URL segment corresponds to an object in the database, and resolution happens by traversing the object hierarchy itself.
At the foundation of the architecture lies ZODB (Zope Object Database), a transactional object database natively integrated into the framework. Python objects are persisted directly, with no need for a relational mapping layer. ZODB supports ACID transactions, multi-level undo and pluggable storage — it is possible to use different backends, including the file-based FileStorage for simple installations.
Acquisition and security
One of the most distinctive mechanisms is acquisition: an object can “acquire” attributes and methods from objects above it in the containment hierarchy. This allows defining configurations, templates and policies at the folder level and having them automatically inherited by all contents below, without duplication.
Zope’s security model is granular: each object can have specific permissions assigned to roles, which in turn are associated with users or groups. This level of control — down to a single method on an object — is unusual for a web application server and enables multi-tenant architectures without code-level modifications.
Through-the-web and CMF
The through-the-web (TTW) architecture allows creating and editing objects, DTML templates and Python scripts directly from the browser, via the ZMI (Zope Management Interface). This approach lowers the barrier to entry for prototyping, although complex projects benefit from filesystem-based development with Zope Products — Python packages that extend the framework with new object types and functionality.
On top of Zope sits the CMF (Content Management Framework), a set of tools for building portals with workflow, metadata, indexing and skinning capabilities. CMF provides the foundational infrastructure for those who need structured content management, without imposing a predefined user interface.
Link: zope.org