[xslt] XSLTPROC performance

[Giulio Rizzo <gr active-media-group com>]

Hi

First of all I introduce myself, I'm Giulio from Italy.
I am required to write some extension function to a libxml compliant xslt 
processor. Actually we use the XSLTPROC that comes with the debian 
distribution. I've red the documentation and the faq and I've find that there 
are two xslt processor that I may use, XSLTPROC and XML::LibXSLT.
The second choise will be easy for me, as I'm already able to register 
function in the perl way. I've tried to made it inside XSLTPROC,  registering 
C modules,  but I cant' get through it. 
The problem is that we made some benchmark (not very extensive benchmark 
indeed) and seems that the XML::LibXSLT solution is 20% -50% slower in 
execution than the XSLTPROC solution. Can anyone confirm or disconfirm this 
results? I've surf your mailing list archivie and the net but I can't found 
comparative benchlmark.
If it is true, than I have to extend XSLTPROC (performance is the highest 
requirement), is there any tutorial how to do this (I've already red the one 
in the homepage od LIBXSLT and the one that comes with the source 
distribution).
Is any other solution alternative to the two I've mentioned? The problem is 
that is about 6 years that XSLTPROC have been used and the new (?) processor 
must give the same results as XSLTPROC.
Last question, the optimum will be to be able to use a java XSLT processor, 
but I must be sure that it is 100% compliant with the results of an XSLTPROC 
execution on the same input.
Sorry for my english and thanks for helping me.

Best regards.

Giulio