The FunctX XQuery/XSLT 2.0 function library is a set of reusable functions for XQuery 1.0 and XSLT 2.0. The project itself is an open source application and framework for developers to create function libraries. This talk will present an overview of FunctX from the perspectives of using the library and as an example of how one would build reusable XSLT and XQuery modules.