xsltproc & callout.extension

So I was wondering why callout numbers weren't appearing in 
my program listings, and then I read this:

http://www.sagehill.net/docbookxsl/AnnotateListing.html

  "Currently line numbering is only available with the 
  Java processors Saxon and Xalan, not xsltproc, because it 
  is done with an extension function."

Oops.  This is annoying, since we've just finishing the DocBook
built system using Ant, which incorporates xslt. Is there any 
plan for xslt to support extensions and, if not, which processor
would you recommend we use to? Do they have their own
limitations?

Thanks,

P.


-pm

http://oceanclub.blogspot.com

"Canadians are always dreaming up a lotta ways to ruin our 
lives. The metric system, for the love of God! Celsius! Neil 
Young!"