SML - A Simpler XML?

by Jan Egil Refsnes

XML is a technological revolution, and XML is easy to use. The official design goals for XML - taken from the W3C XML 1.0 Recommendation have been:

• XML shall be straightforwardly usable over the Internet.
• XML shall support a wide variety of applications.
• XML shall be compatible with SGML.
• It shall be easy to write programs which process XML documents.
• The number of optional features in XML is to be kept to the absolute minimum, ideally zero.
• XML documents should be human-legible and reasonably clear.
• The XML design should be prepared quickly.
• The design of XML shall be formal and concise.
• XML documents shall be easy to create.
• Terseness in XML markup is of minimal importance.

Many developers have already started to use XML. Most of them are using small subset of XML, consisting only of element tags without attributes, entity-references and DTD. Naturally the question arises: is XML simple enough?

In a recent message to the XML developers' mailing list XML-dev, Don Park defined SML as XML with:

• No Attributes
• No Processing Instructions (PI)
• No Document Type Declaration (DTD)
• No non-character entity-references
• No CDATA marked sections
• Support for only UTF-8 character encoding
• No optional features

Is Don Park right? Do we really need attributes as long as they can be replaced with standard elements. Do we ever use entity references? Is there a need for a DTD?

Anyone in the world can understand Simple XML:

<note>
  <from>Jani</from>
  <to>Tove</to>
  <message>Remember me this weekend</message>
</note>

So why should we make it more difficult?

How are the leading figures in the XML community reacting to this? Is it really necessary to create a new XML? Why can't we just use XML without the difficult features?

Read the full story at: http://www.xml.com/pub/1999/11/sml/index.html

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