The W3C has released the “Namespaces in XML” specification as a W3C Recommendation. Teaming up with W3C’s Extensible Markup Language (XML) Recommendation, this new specification allows authors to mix two or more XML-based languages in one document without conflict or ambiguity, thus promoting the modular development and reuse of XML languages and applications. The “Namespaces in XML” specification resolves potential name clashes by using the Web addressing infrastructure. Each element name in a document may be prefixed with a unique address, thus precisely qualifying the name. The modularity and simplicity of XML technology combined with namespaces paves the way for future developments, such as the work in progress in W3C’s XML Schema Working Group, and data exchange based on W3C’s Resource Description Framework (RDF) architecture. The “Namespaces in XML” specification was created and developed by the W3C XML Working Group, which includes key industry players such as Adobe, ArborText, DataChannel, Hewlett-Packard, IBM, Inso, Isogen, Microsoft, NCSA, Netscape, Oracle, SoftQuad, Sun Microsystems, Texcel, Vignette, and Fuji Xerox; as well as experts in structured documents and electronic publishing.