Translating XHTML or XML to WML using XSLT 2.0

Hello everybody!
I'm Luana, student of computer engineering and I'm researching how to
convert a XML or XHTML for WML. I saw in some posts that there is a
lot of people that works or have already worked with that as Mr.
Andrew Welch, who did it as part of  his dissertation 5 years ago.

I would Like to know how I can download some library and the
documentation because I need to do the transformation in a server  (
I'm looking for documentation on http://www.w3.org/TR/xslt20/  ).  Any
hints are welcome.

 Thank you!

--
Luana Knoff