IBM posted information on its website Tuesday highlighting the evolutionary changes built into HTML 5. As the author points out, HTML has changed very little since 1999, when HTML 4 was released. Web developers instead have turned their attention to CSS, XML, and Ajax, all of which provide incredible functionality and have a much steeper learning curve than HTML.
According to the website,
This new version of HTML—usually called HTML 5, although it also goes under the name Web Applications 1.0—would be instantly recognizable to a Web designer frozen in ice in 1999 and thawed today. There are no namespaces or schemas. Elements don't have to be closed. Browsers are forgiving of errors. A p is still a p, and a table is still a table.
HTML 5 was explicitly designed to degrade gracefully in browsers that don't support it. The reason is simple: We are all cave people. Browsers now have tabs, CSS, and XmlHttpRequest, but their HTML renderers are stuck in 1999. The Web can't move forward without accounting for the installed base. HTML 5 understands this. It offers real benefits to page authors today while promising even more to page readers tomorrow as browsers are slowly upgraded.
It remains unclear when HTML 5 will be fully adopted as a specification, but the new developments are certainly worth keeping in mind as you and your students dig deeper into XML and various scripting languages to achieve eye-catching and competitive websites.