From what I've read, the MSXML components that IE uses for XML processing don't support XPath 2.0, thus they are missing some functions I would like to make use of (like lower-case() ). It appears from various Google searches that custom functions can be written in an XSLT file, would be nice to duplicate some XPath 2.0 functionality, but I've yet been able to get this to work. Are extension functions just not possible with the MSXML dll's or can someone point me in a different direction? Here is my current code:

<xsl:stylesheet xmlns:xsl="" 
extension-element-prefixes="func com"
	<func:function name="com:something">
	      <func:result select="'blahblah'" />
When trying to do a transform that has com:something() in it, I will get an error saying Namespace http://www.some.domain/XSLT/Common does not contain any functions.
Some references: