RE: output .net register directive

> michael, this might be a very stupid question - but what is a 
> xslt serializer?
> 

It's the piece of software that takes the result tree generated by your
stylesheet and turns it into a stream of characters (or bytes) representing
an XML or HTML document, under the control of the xsl:output declarations.

The significance is that you don't have to invoke the XSLT serializer. For
example, if you run a transformation in Mozilla the result tree is passed
straight to the HTML rendering engine, without first serializing it.
Similarly, in the MSXML world you often send the transformation result to a
DOM and then use the DOM serializer, which doesn't understand things like
xsl:output and disable-output-escaping.

Michael Kay
http://www.saxonica.com/