Why XML?

• Hypertext: text with links to other texts.
• Markup Language: annotations for structure of a text.

HTML design:

• HTML markup is designed to provide logical structure of information intended for presentation as Web pages.
• HTML contains a fixed set of markup tags, and also defines their semantics.

  <h1>Why XML?</h1>
  The Web today: everything is <b><a href="http://www.w3.org/MarkUp/">HTML</a></b> - 
  <i>HyperText Markup Language</i>.

HTML syntax is formally defined (but most HTML is not valid).

CSS (Cascading Style Sheets) allow separation of logical structure and page layout.

But: Although exact layout can be defined separately in CSS, HTML is designed for hypertext - not for information in general!