XSLTAL info
XSLTAL is a partial reimplementation of the Zope TAL templating syntax, which requires only an XSLT processor.
The tal2xslt transform used internally to implement this was donated to Cocoon by Christian Stocker of bitflux.org, so that we can collaborate on maintaining this and spreading the word.
For more information see the XSLTAL page at bitflux.org.