Gareth has worked for DecisionSoft for 4 years. In this time he has acquired a deep knowledge of XML and related technologies, including XML Schema, XPath and DOM. Gareth has contributed to a number of major Open Source projects, has commit access on the Apache Xerces project and sits on the Project Management Committee for XML Products. He also runs Pathan, DecisionSoft's Open Source XPath 1 and XPath 2 implementations. Gareth has a high level of expertise in XML standards and has contributed as a technical reviewer to several key XML publications.

Christian Nentwich is Technical Director of Systemwire Ltd. Systemwireproduce the xlinkit suite of products, which is aimed at semantic, orbusiness-level validation of XML documents. xlinkit's rules, which areexpressed in the CLIX constraint language, deal with issues likechecking against reference data, multi-documents checks and complexinternal constraints, that traditional schema languages cannot support.Christian is also chairman of the Validation Working Group of theFinancial Products Markup Language (FpML). The group defines validationrules for financial derivative trades expressed in FpML.

In his 4 years at DecisionSoft, Paul Warren has gained extensiveexperience of real world applications of XML validation. As part ofDecisionSoft's involvement with many UK government e-Filing projects,Paul has played a key role in translating business data constraints intoXML validation components, and has found that from a businessperspective, the split between what can and cannot be encompassed in XMLSchema validation appears arbitrary. As a result, these validationcomponents are made up of standard XML Schema validation augmented witha proprietary rules engine. DecisionSoft are keen to develop astandardised mechanism for beyond-schema validation, and feel thatrecent developments such as XPath2, XQuery, and the general move towardsmaking schema validation information available in applications, thefoundations for an extremely powerful validation system are already inplace.

Alberto Massari started working on XML technologies in late 1998, working for Object Design in the team that built eXcelon, the first XML Database. He now works for the Stylus Studio team managing the XQuery and XSLT processors and the DTD/XMLSchema editors bundled inside this IDE for XML development. He has contributed to a number of major Open Source projects, and has commit access on the Apache Xerces project.