From the website:

  This product seeks to establish website production harmony
  through the seamless integration of the three separate domains:
  Presentation, Content and Logic.

Zope Page Templates comprise a trio of Zope products which allow the complete
conceptual separation of design (presentation) elements from business logic
elements in a Zope-driven web application.  In essence this allows web
designers to work on design templates for a Zope-based site using their
favourite WYSIWYG web design tools.

The ZPT implementation includes the Template Attribute Language (TAL), a web
templating language (i.e. analogous to, say, PHP or Zope's own DTML).  TAL is
an intentionally simple language, since in the ZPT paradigm all business
logic should be implemented externally to the page templates in Python (or
Perl) Script objects.

See also:  http://www.zope.org/Documentation/Articles/ZPT{1,2}

Author: Evan Simpson <evan@digicool.com>  
WWW:    http://www.zope.org/Members/4am/ZPT

-- Johann Visagie <wjv@FreeBSD.org>