Parsing XML/XSLT

[veracon]

Hello,

I'm looking to use XML and XSLT for templates in a system I'm writing,
however I'm not really sure which parser is the "best". Basically,
which library has the most features, and which is the most supported?

A guide I saw mentioned importing xml.xslt, however it appears the xml
module/package contains pretty much nothing - xml.xslt outputs an
exception, No module named xslt.

Help?