XHTML documents, which means they can be viewed and edited using normal HTML editors or XHTML compliant tools (a big advantage compared to other template languages used for Web applications). Templates can also be checked for XHTML compliance so you can be fairly confident that they will automatically expand into proper XHTML. However, these page templates are not meant to be rendered as is. Instead they are marked up with additional elements and attributes in special XML namespaces (see below). This additional information is used to describe how the page template should ultimately be processed. Here are some basic examples. To conditionally include a particular element, like a div element, simply add the tal:condition attribute to the element as follows: <div tal:condition="..."> ... </div> To control what appears inside an element, use the tal:content attribute like this: <h1><span tal:content="..."/></h1> ... Finally, to introduce or replace values of attributes use the tal:attributes attribute as below. You can use Python to alter the href at runtime. <a href="" tal:attributes="href python:'http://someurl.com/%s'%someobject">...</a> This is a very cursory explanation of Zope Page Templates. The behavior of Zope Page Templates is almost completely described by a template language, fixed on TAL, TALES, and METAL specifications: Template Attribute Language (TAL), Template Attribute Language Expression Syntax (TALES), Macro Expansion Template Attribute Language (METAL). Notable software using Zope SchoolTool is an open source student information system that uses Zope. Plone is an open source content management system that uses Zope. See also Pylons project Django web2py Content management (CM) Content management system (CMS) Web content management system (WCMS) Plone Naaya ERP5 Twisted References External links 1995 establishments in Virginia Cross-platform free software Free content management systems Free software programmed in Python Python (programming language) web frameworks Software companies based in Virginia Software companies established in 1995 Web development software Web server software for Linux Software companies of the United States it:Zope 3 pt:BlueBream