Jeni Tennison is an independent consultant specializing in XSLT and XML Schema development. She trained as a knowledge engineer, gaining a Ph.D. in collaborative ontology development, and has since become a consultant working in a variety of areas including publishing, water monitoring, and financial services. She is the author of XPath on the Edge and Beginning XSLT and is one of the founders of the EXSLT initiative to standardize extensions to XSLT and XPath. She is an invited expert on the W3C XSL Working Group, and she was voted ActiveState Activator's Choice XSLT Programmer of the Year in 2002. She spends much of her spare time answering people's queries on the XSL-List and xmlschema-dev mailing lists.