HTML 5, the future of the Web

HTML 5 officially will become the format of Web pages to succeed to the current version 4.0. The standard is being defined by the W3C. Since 2004, the independent working group WHATWG id working to define a standard format for web page and to replace both HTML 4 and XHTML, while maintaining compatibility. Its success prompted the W3C to turn away from XHTML 2 on which he barely achieve unanimity and from proposed standards on forms. In fact the HTML format 5 goes much farther than that, as we will see ...

History

The last specification of HTML 4 was published in 1999 and since this date, the W3C turned to XHTML.
But XHTML 2 causes the discord, in addition to the fact that it is incompatible with preceding standards, one reproaches it its pure document orientation whereas the Web becomes 2.0 and needs more and more applications and uses various media.
From this opposition in 2004, an independent group supported by Apple, Mozilla and Opera is born, the WHATWG (Web Hypertext Application Technology Working Group) which undertakes the definition of a successor for HTML.
On March 3, 2007, the W3C announces that it restart the work on HTML to give it a successor.
The new specification of the W3C has the same author as that of the WHATWG, Ian Hickson.

Overview

The new format is not any more a simple format of document, but also a support for current Web applications such as forum, etc and a purpose is to facilitate interoperability.
It has two formats in one, HTML and XHTML 5, the first with a doctype, the second with only at the beginning the line <?xml version= ""?>.
It integrates DOM Level 2 for HTML.
Syntax is such as a page can be parsed as an XML document if it is designed for that, but it keeps incompatible characteristics from HTML, such that the tags without contents which end by ">" and not "/>" both being supported by browsers, mais not by XML parsers.

Applications

HTML 5 is aimed at Web pages and Web applications. Moreover the definition was called Web Application 1.0 before changing name for being better posed as a successor to HTML 4.
Some applications such as forums, wikis, purchasing systems, searching systems, e-mail clients, instant messaging clients, discussion software, online document editing, sites sharing resources, and Web 2.0 sites in general, are now popularized and require a format of document more adapted to that.
Features of HTML 5 include graphics and images, which will make it possible to make animated pages, multiplayer online games.

Differences between HTML 4 and HTML 5

Even if the format is still in work, certain components are acquired. It is wise to know them because some practices should be adopted right now, such as suppression of frames.

HTML 5 is compatible with HTML 4 and XHTML although some tags become obsolete. it can take two forms, a traditional one with HTML tags, the other in XML. It comprises new forms, support new media, and adds a support for drawing and images. The new format will integrate another specification in progress: Web Forms 2.0.

New elements

Canvas

It is a background on which one can draw and thus new graphic elements may be added to the interface. It is inspired by the syntax and functions from Java.
One can put several canvas in a Web page.
On the canvas one can perform transformations as scaling, rotating, translating.
Varied figures are available: rectangles, Bezier's curves, arc, with functions of filling and stroke. And also clipping on the edges of the canvas.

Audio and video

The video tag allows to embed a video in the document. It is accompanied by a src attribute to indicate the file, but also by attributes like start, stop, autoplay etc which define the behavior of the video.
The audio tag is the equivalent for sound files.

Section

The section tag makes it possible to divide (or subdivide) a document into semantic parts. They are used to create an outline, table of contents. The sections can be chapters. They differ from div tag which has a role of presentation.
A section is completed with a header and a footer.

Modified elements

a, optional href

Removing href makes it possible to use the attributes of a on a dynamic link, in conjunction with onclick but without providing URL (the URL could be defined in a script).

script, the async attribute

A script is by default executed at loading, while it will be executed at the end of parsing of the HTML page when the defer modifier is added. But if it is the async modifier that is present, then it is executed in an asynchronous way, therefore independently of the display of the page and according to the availability of resources, as Ajax.

Removed elements

Frames disappear. Consequently the tags frame, frameset, noframe are not any more part of the format.

HTML 5 will replace HTML 4

HTML 5 is a replacement for the current HTML 4 language, standard of the W3C. Its definition is supported by major actors of the Web, Google, Apple, Mozilla and Opera. Microsoft support it in Internet Explorer 9 the largely most used browser.
The author of the HTML 5 definition became employed of Google.
Google announced Google Gears tool which makes it possible to run Web applications without connection deprecated and replaced by the equivalent functions in HTML 5.
The interest of Google is to suppress the operating system and to generalize the use of on line applications to the desktop station, its interest thus is in HTML 5.
Microsoft wanted to promote Silverlight with all background standards technologies from the company, as XAML but has shifted its strategy and now support HTML 5 that is implemented in IE9.

HTML 5 vs Silverlight

Silverlight is based on the .NET platform and cannot be regarded as a universal environment. Remain to know if HTML 5 can be compared with Silverlight...

In fact the features of Canvas of HTML 5 are similar to those of Silverlight. Vectorial figures are drawn into and one add images in both cases. That opens the way to elaborate interfaces with animations and plays.
The video and audio tags of HTML 5 have also equivalent in Silverlight and the two environments work with Ajax.
Both HTML 5 and Silverlight have an offline mode for web applications. But we can choose the programming language on the latter while the former knows only JavaScript.
In conclusion the two environments are equivalent and differ mainly by the programming style and the details.

Implementation by browsers

All browsers support partially HTML 5. The Google Chrome Frame plugin will let the old version of Microsoft's browsers works just as Chrome with HTML 5!

For a direct test in you browser:

• List of HTML 5 form objects.
• List of HTML 5 new attributes.

Conclusion

The failing of XHTML 2 and its limitations open the way to HTML 5 which not only improves HTML 4 and XHTML 1 but also is a response and an alternative to the Silverlight environment. HTML 5 is viewed as an alternative to Flash also, this is the case for Apple.

W3C started the standardization of the new HTML. It will undoubtedly be a long time before it does become a recommendation, but most of its functionalities are beeing implemented by browsers now, including Internet Explorer 9.

More information

• HTML 5 specification by the WHATWG. Written by Ian Hickson.
• HTML 5 specification by the W3C. The W3C resumes work on HTML starting from the document of the WHATWG. Same author.
• Canvas. The graphics tag is now implemented in all browsers. Tutorial and examples.