While a well-formed document is well-formed because it follows rules defined by the XML spec, a valid document is valid because it matches its document type definition (DTD). The DTD is the grammar ...

Nearly everyone is talking about XML (Extensible Markup Language) these days. But few understand what it's really all about. XML's proponents claim it will cure everything that's wrong with HTML and ...

SGML (standard generalized markup language) is a standard for how to specify a document markup language or tag set. Such a specification is itself a document type definition (DTD). SGML is not in ...

The Web is built on open standards. Until recently, XML (search ) was considered one of them. Now, Scientigo is claiming that two of its patents cover one of XML's fundamental principles and is ...