The ZModelization is a tool to help you design a model.
It lets you create and edit the model through a web interface, that is to say that every single element being part of the xml-model can be modified through easy-to-use web forms. It has some niceties, such as the possibility to create a relationship and its inverse along with the foreign key if needed in a single operation, or the ability to create in a single click a sub-entity having all of its parent's attributes and relationships.
Last, you may validate the model, generate the database schemas and the python code for your model, just by a few mouse clicks.
To install the tool, you first need to install Zope
(http://www.zope.org). Then copy the directory ZModelizationTool/ into
zope's Products
directory (located in $ZOPE_HOME/lib/python/ in
a brand new zope installation2.6).
Run Zope, access to the zope management interface and create a 'ZModelization Tool' where appropriate (for example, in the root directory). That's it.