Noting that HTML itself hardly progressed since HTML 4 became a W3C standard in 1999, Elliotte Harold Rusty highlights key features of a proposal referred to as HTML 5 in his latest IBM developerWorks article, New elements in HTML 5:

Three major browser vendors—Apple, Opera, and the Mozilla Foundation—came together as the Web Hypertext Application Technology Working Group (WhatWG) to develop an updated and upgraded version of classic HTML. More recently, the W3C took note of these developments and started its own next-generation HTML effort with many of the same members. Eventually, the two efforts will likely be merged. Although many details remain to be argued over, the outlines of the next version of HTML are becoming clear.

Harold notes that HTML 5 is completely backward-compatible with earlier versions of HTML: content authored with HTML 5 tags will gracefully degrade in older Web browsers.

The tags in HTML 5 focus on providing more structure to HTML documents, providing better feedback to users, and including audio and video media types in HTML pages.

About structural elements, Harold writes that:

HTML 5 adds new elements to specifically identify common [stuctural] constructs:

• section: A part or chapter in a book, a section in a chapter, or essentially anything that has its own heading in HTML 4 header: The page header shown on the page; not the same as the head element
• footer: The page footer where the fine print goes; the signature in an e-mail message
• nav: A collection of links to other pages
• article: An independent entry in a blog, magazine, compendium, and so forth

Among the interactive elements proposed in HTML 5 is a datagrid tag, for example:

The datagrid element serves the role of a grid control. It's intended for trees, lists, and tables that can be updated by both the user and scripts. By contrast, traditional tables are mostly intended for static data... A datagrid gets its initial data from its contents: a table, select, or other group of HTML elements...

Harold notes that the new elements aim to provide standard solutions to problems that each developer or project currently solves in an ad-hoc manner.

What do you think of the proposed HTML 5 tags? What tags would you like to see in HTML that are not part of HTML 5?