Whats the difference between XML and SGML?
XML and SGML are conceptually the same. The key differences are that for XML, several complex, rarely used features were removed which made it easier to implement, and several features were added to support e-commerce. The features that were removed should not impact most applications, especially those built from scratch in XML. The key items removed are: 1) Tag minimization is no longer allowed. 2) Aggregate Connectors are no longer allowed in element content models. 3) SGML Inclusions and Exclusions to specific element content models are no longer allowed. The key items added are: 1) XML introduces a new notation for empty tags, namely the notation. 2) A DTD is not required to produce valid XML, as long as the document is “well formed”. NOTE: A more detailed analysis of the specifics may be found in “SGML to XML Conversion Strategies” by Richard Lander. XML vs. SGML – which should I start with? I’m starting a new project and considering the use of one of the structured markup standar
