Extreme XML - Extending XSLT

Lately, I have been working with quite a bit of XML within the .NET libraries. In certain cases, I could do a lot with the forthcoming XPath v2 (see prior posting) but that's not yet available for development. I came across Dare Obasanjo's article on EXSLT: Enhancing The Power of XSLT. It provides functions that support regular expressions, set based operations, and date-time processing. This hits the spot (for the moment).