XSLT = XSL Transformations.
The specification can be found at http://www.w3.org/TR/xslt
[Explain what XSLT is.] [Point to http://starbase.neosoft.com/~claird/comp.text.xml/XSLT.html also.]
Two implementations are already in industrial production. Zveno's TclXSLT .... Early in development, Zveno also wrapped James Clark's XSL processor with TclBlend (!). This is now obsolete. Zveno's standard TclXSLT, like its TclXML, comes in both pure-Tcl and compiled-with-C flavors.
AK I do not believe so, at least not at first glance. At its core XSLT is a tree transformation language.
[Recommend Mike Kay's XSLT Programmer's Reference.]