1. Future Markup Steven Pemberton CWI, Amsterdam Chair, W3C HTML Working Group

2. HTML as an SGML Application zSGML: an international standard in 1986 zIt is a Meta-language that describes data formats, using DTD’s (Document Type Definitions) zDescribes structure, not presentation HTML as SGML Application zUsed for HTML in early 1990’s

3. HTML zNetscape and Microsoft start adding to HTML: mostly presentation-oriented tags (like ) zThe World Wide Web Consortium (W3C) started effort to: yKeep HTML Pure yDo presentation via Cascading Style Sheets (CSS)

4. CSS zCSS is a separate language from HTML that allows you to specify how an HTML document, or set of documents, should look zSeparates content from presentation zHTML is a structure language again

5. Advantages of CSS zMakes HTML easier to write (and read) zYou can define a house style zCompatible: you can still see the content on non-CSS browsers zPages are much smaller zAccessible to sight-impaired z...

6. By the way... zCheck your logs: more than 90% of people browsing now use a CSS-enabled browser zYou never need to use the and elements again!

7. Documents zHTML was designed for just one sort of document (scientific reports), but is now being used for all sorts of different documents zYou could use SGML to define other sorts of document, but SGML is notoriously hard to fully implement

8. Enter XML zXML is a W3C effort to simplify SGML zIt is a meta-language, a subset of SGML zOne of the aims is to allow everyone to invent their own tags zDTD is optional: a DTD can be inferred from a document

9. Consequences zThe requirement of being able to infer a DTD from a document has an effect on the languages you can define: yClosing tags are now required........ yEmpty tags are marked specially (or etc)

10. Consequences 2 zCDATA sections must be marked as such (if they contain “<”, “&” etc.): <![CDATA[... script content... ]]>

11. By the way: is not like Not Like This XML An underlying problem with HTML is that... You could use SGML to define... But Like This XML An underlying problem with HTML is that … You could use SGML to define...

12. Consequence of XML zAnyone can now design a (Web-delivered) language zCSS makes it viewable Steven Pemberton CWI Kruislaan 413 1098 SJ Amsterdam

13. So do we still need HTML? zXML is still a meta-language zThere is still a perceived need for a base- line mark-up zHTML has some useful semantics, both implied and explicit (search engines gladly use it, for instance)

14. HTML as XML application zClean up (get rid of historical flotsam) zModularise – split into separate parts yAllows other XML applications to use parts yAllows special purpose devices to use subset zAdd any required new functionality (forms, better event handling, Ruby)

15. Differences HTML:XHTML zBecause of the difference between SGML and XML, there are some necessary differences, for instance: yUse lower case: not yAttributes are always quoted: yAnchors use id attribute not name (and not just on by the way):

16. Example Virtual Library Moved to vlib.org.

17. Namespaces A Math Example The following is MathML markup: 3 x

18. Semantics Differences zPresentation  use CSS zLinks  use Xlink or Schemas zForms  use CSS? zImages etc.  use Xlink z(Natural) language of elements  use xml:lang attribute

19. Transition zXHTML 1.0 has been carefully designed to make use of ‘quirks’ in existing HTML browsers zUse of a small number of guidelines allows XHTML to be served to HTML browsers

20. Examples of Guidelines zUse space before / of empty elements: zUse name= and id= on : …

21. Conclusions zXML with related technologies gives you the freedom to define and deliver your own document types zHTML is still needed as a base-line markup zThe new HTML gives a transition path to the future

22. The State of Things zNew generation of XML+CSS browsers emerging zMany XML applications appearing zMajor companies planning XML as output (Adobe PDF, MS Office 2000) zNow: HTML4 as XML, Conversion software zThis year: Modules, Subsets, Extensions, Profiles, New Forms

23. To Find Out More zAll XHTML developments are made public at www.w3.org/Markup zMembers of W3C can also look at www.w3.org/Markup/Group