The xslt() Virtuoso/PL function applies a given stylesheet to a given source XML document and returns the transformed document. There is no restriction to what a VSP page can output, this is usually HTML but can be XML. The function http_xslt() allows a stylesheet to be applied to a whole output of an VSP page before it is sent to the user agent. Functions xslt_sheet() and xslt_stale() allow you to create and destroy a stylesheet dynamically. Function xmlupdate() is convenient for very simple "search-and replace" transformations.