Let me first say "Welcome back" to Jeni :o)
As you know, XSLT 2.0 supports function libraries: you construct a
stylesheet that includes <xsl:function> definitions, and then import
that into other stylesheets as appropriate. Hopefully libraries of
functions, such as those that already exist in EXSLT and FXSL, will be
constructed in this way.
And to confirm that FXSL for XSLT 2.0 is making heavy use of xsl:function.
Cheers,
Dimitre Novatchev [XML MVP],
FXSL developer, XML Insider,
http://fxsl.sourceforge.net/ -- the home of FXSL
Resume: http://fxsl.sf.net/DNovatchev/Resume/Res.html
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list