XSLT stylesheets

XSLT ‘stylesheets’ (transformation instructions) are themselves XML documents
Modular approach: can have libraries of XSLT functions
Can merge lots of documents into a single result
With an extension function (or using 2.0) can generate multiple outputs from a single source
Extensive library of stylesheets is available for TEI
System developer needs to learn XSLT; users don't
Large community of XSLT users on XSL-LIST, all eager to help ...