Diazo/XDV Approach to Plone Theming
Using XDV a theme can be applied to a dynamic website by identifying such things as placeholders for replacing theme file elements with dynamic elements, markup in the dynamic website, and parts of the theme and/or dynamic website that are superfluous. For every of the above mentioned cases, XML rules are to be set. As soon as there are theme HTML file and a rules XML file, they can be compiled into a single XSLT file.
The Diazo (XDV) theming engine enables themes to be created without reference to the various markup generating technologies which make up a Plone page.
See Diazo/collective.xdv getting-started guide at: http://pypi.python.org/pypi/collective.xdv