Amongst the new features squarely targeted at application developers, HTML 5 introduces a number of new Javascript APIs. These can be used in conjunction with corresponding HTML elements and include:
- A 2D drawing API which can be used with a new canvas element for rendering graphs, game graphics, or other visual images on the fly.
- An API that allows a web application to register itself for certain protocols or MIME types.
- An API that introduces a new caching mechanism to support off-line web applications.
- An API for playing video and audio which can be used with the new video and audio elements.
- A history API that exposes the browsing history and allows pages to add to it to facilitate better back-button support in AJAX applications.
- Cross-document messaging which provides a means by which documents can communicate with each other regardless of their source domain, in a way designed to prevent cross-site scripting attacks.
- A drag & drop API to use in combination with a draggable attribute.
- An editing API to use in conjunction with a new global contenteditable attribute.
- A new network API to enable web applications to communicate with each other on local area networks, and to maintain bidirectional communications with their originating server.
- Client-side persistent storage with JavaScript APIs for key/value pairs and support for embedded SQL databases.
- Server-sent events in combination with the new event-source element which will facilitate persistent connections to remote data sources and largely eliminate the need for polling in web applications.
A number of new presentation elements have also been introduced with support for familiar page components such as headers, footers, figures, dialog (used to mark-up a conversation), and navigation. There is a new datagrid element which will support interactive tables and trees, a datalist element for combo boxes, and a progress attribute which represents the completion of a long running task. Support for RSS feeds within the page markup has also been added.
For forms the input element's type attribute has new support for dates, times, emails and URLs, so that the browser can provide the user interface elements, for example a calendar date picker or integration with the user's address book, and submit the data in a defined format to the server.
HTML 5 also drops support for some well-know features. The most notable is support for frames, which have long been considered detrimental to accessibility and usability. It should be noted that dropped features will continue to be supported by browsers that also fully support the HTML 5 standard, since support for legacy versions of HTML will remain for many years.
The development of HTML 5 is being stewarded by the W3C's HTML Working Group, founded in March 2007. The group operates entirely in public with nearly 500 participants including members from Apple, Google, IBM, Microsoft, Mozilla Foundation, Nokia and Opera.
"HTML is of course a very important standard," said Tim Berners-Lee, author of the first version of HTML and W3C Director. "I am glad to see that the community of developers, including browser vendors, is working together to create the best possible path for the Web. To integrate the input of so many people is hard work, as is the challenge of balancing stability with innovation, pragmatism with idealism."
HTML 5 will eventually supersede HTML 4 but the finalisation of the specification is still quite some way off. The current plan is to have it available in a preliminary candidate recommendation form in the middle of 2009 and as a formal, final recommendation by September 2010.
Community comments
XHTML?
by Matthias K.,
Re: XHTML?
by Nicholas Piasecki,
Re: XHTML?
by Samuel Santos,
HTML5 and Flex, Silverlight, etc.
by Warren Ayers,
HTML 5.0 is a "panic mode" draft.
by Francois Ward,
XHTML?
by Matthias K.,
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Just wondering: what is the reason for continuing the SGML-based HTML standard? I thought XHTML had been introduced to cope with the complexity issues of SGML, and therefore HTML? So why a HTML5 and not an XHTML2?
Re: XHTML?
by Nicholas Piasecki,
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IMHO, one of the main reasons is that XHTML2 (which does exist in some draft form or another, I believe) breaks compatibility with the existing Web so badly while not offering enough super useful features to warrant such a break. It uses XForms, for example, which is architecturally and semantically clean but completely (and I do mean completely) different from the forms that we've been using since the dawn of the World Wide Web. Since it's so hard to get browsers that implement the *existing* HTML and CSS standards cleanly and correctly, much less to get content generators (developers, tools, users) to generate (X)HTML correctly, the rigid and clean beauty of XHTML2 is definitely pie-in-the-sky Utopia for everything but the most well-maintained and insulated corporate intranets and internal Web applications.
In other words, the world should not end with a "non-well-formed XML" screen of death if Joe HTML writer forgets to close a tag or escape an ampersand in an anchor href.
Hope that makes sense.
HTML5 and Flex, Silverlight, etc.
by Warren Ayers,
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I think the proposed elements to HTML 5 sound great, but I would have liked them a lot more 5 years ago or so. With a final draft still two years off, and the potential adoption of rich interfaces via products like Flex, Silverlight, etc., which should only accelerate in those two years, I don't know... Has HTML perhaps had its day in the sun?
I'm personally looking forward to the rich features and potential aesthetics that Flex or Silverlight will [should!] provide. I know the adoption is not a guarantee—-anyone remember Java applets?—-but I kind of hope it is. If so, these products will have a head start of several years, and HTML 5 may be too inferior by the time it's ready.
I know, I know. Flex/Silverlight probably won't ever be suitable for the average Joe who wants to list his hobbies or recipes on his own web page, but does Joe need these proposed new features? Is HTML 4 enough?
LOL! Or maybe I'm just biased because I want something new to play with. HTML 5 just doesn't get my blood pumping! :o)
HTML 5.0 is a "panic mode" draft.
by Francois Ward,
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HTML 5.0 is made because they are having issues getting XHTML going, so they're going back to the drawing board and updating HTML 4 to cope with the new world. But they missed the point... Adding a new datagrid component isn't going to help when no one still can agree on what is a good datagrid...
They should just admit defeat and realise that they'll never get tools to handle 100% of the scenarios (which is what the W3C and its derivatives keep trying to do...instead of having tools that let you handle MOST scenarios, and a way to make up the bits that aren't there), and let third parties do it.
I think the trend shows how it is going to be successful: libs like ExtJS, GWT, ASP.NET controls, everything use the existing "inadequate" stuff and builds on top of it... So make a clean, simple, low level draft that lets you build on top of it. Leave the implementations to the rest. That is the only thing that has worked so far...throwing another draft that tries to solve all problems will not work...they've tried enough times already.
HTML 5.0 is too plump. Even the open source browsers will take forever to implement that. Its just more tags that will have bugs in em and that we'll have to deal with for backward compatibility for the next decade.
Re: XHTML?
by Samuel Santos,
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HTML5 is not based on SGML anymore.
Take a look at www.w3.org/TR/html5/#html-0.