tag libraries implementation approaches logicsheet, writing module-based, installing 2nd module-based, writing with TaglibHelper most popular samples Util tag library simple example template toolkit AxKit Language interface for AxKit Language module implementation features generating and transforming XML, suited for generating content home page of syntactical difference from Perl and XML transforming content 2nd templates, stylesheets evoking with name attribute rules xsl:template element basic building block of match attribute pattern expression mode attribute for rules Tip, chosing best grammar (or data) model