HTML 5

Infobox file format
name = HTML (HyperText Markup Language)
icon =
extension = .html, .htm
mime = text/html
type code = TEXT
uniform type = public.html
owner = World Wide Web Consortium
genre = Markup language
container for =
contained by =
extended from = SGML
extended to = XHTML
standard = [http://www.w3.org/html/wg/html5/]

HTML 5 (HyperText Markup Language 5) is planned to be the fifth major revision of the core language of the World Wide Web, HTML. When HTML 5 is expressed in XML, it is called XHTML 5.

The ideas behind HTML 5, originally referred to as "Web Applications 1.0", were pioneered in 2004 by the Web Hypertext Application Technology Working Group (WHATWG); HTML 5 incorporates "Web Forms 2.0", another WHATWG standard.The HTML 5 standard was adopted as the starting point of the work of the new HTML working group of the W3C in 2007.The working group has published the First Public Working Draft of the specification on January 22, 2008. [ [http://www.w3.org/TR/2008/WD-html5-20080122/ HTML 5: A vocabulary and associated APIs for HTML and XHTML.] W3C Working Draft 22 January 2008.] The specification is ongoing work, and expected to remain so for many years.cite web
url = http://wiki.whatwg.org/wiki/FAQ#When_will_HTML_5_be_finished.3F
title = When will HTML 5 be finished?
publisher = WHATWG Wiki
accessdate = 2008-06-14
work = WHATWG]

New markup

HTML 5 provides a number of new elements and attributes that reflect typical usage on modern Web sites. Some of them are technically similar to tag1|div and tag1|span tags, but have a meaning, for example tag1|nav (website navigation block) and tag1|footer. Such tags would facilitate indexing by search engines and handling by small-screen devices or voice readers for the visually impaired.Fact|date=August 2007 Other elements provide new functionality through a standardized interface, such as the tag1|audio and tag1|video elements. [IBM developerWorks [http://www.ibm.com/developerworks/library/x-html5/?ca=dgr-lnxw01NewHTML New elements in HTML 5: Structure and semantics] ]

Some deprecated elements from HTML 4.01 have been dropped, including purely presentational elements, such as tag1|font and tag1|center, whose effects are handled by CSS. There is also a renewed emphasis on the importance of DOM scripting in Web behavior.

New APIs

In addition to specifying markup, HTML 5 specifies scripting application programming interfaces (APIs). [ [http://www.w3.org/html/wg/html5/diff/#apis HTML 5 differences from HTML 4 - APIs] W3C] Existing Document Object Model (DOM) interfaces are extended and de facto features documented. There are also new APIs, such as:
* Immediate-mode 2D drawing
* Timed media playback
* Storage
* Offline
* Editing
* Drag and drop
* Messaging/Networking
* Back button management
* MIME and protocol handler registration

Differences from HTML 4

Here is a cursory list of differences and some specific examples:
* New parsing rules oriented towards flexible parsing and compatibility
* New elements – section, video, progress, nav, meter, time, aside, canvas
* New input attributes – dates and times, email, url
* New attributes – ping, charset, async
* Global attributes (that can be applied for every element) – id, tabindex, repeat
* Deprecated elements dropped – center, font, strike

Error handling

An HTML 5 browser should be flexible in handling incorrect syntax, in contrast to XHTML, where such errors must not be ignored. HTML 5 is designed so that old HTML 4 browsers can safely ignore new HTML 5 constructs. In contrast to HTML4, the HTML 5 specification gives detailed rules for lexing and parsing, with the intent that different compliant browsers will produce the same result in the case of incorrect syntax.cite web |url= http://wiki.whatwg.org/wiki/FAQ |title=FAQ – WHATWG Wiki |accessdate=2008-02-25|work=WHATWG ]

Ogg controversy

HTML 5 introduces new ways of inserting sound and video in webpages with the and elements. Previously, the specification recommended the use of Ogg formats Vorbis and Theora, but this recommendation was later removed [cite mailing list |url=http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2007-December/013135.html |title=whatwg Video codec requirements changed |date=date|10 Dec 2007 |accessdate=2008-02-25 |mailinglist=whatwg mailing list |last=Hickson |first=Ian] after Applecite mailing list |url=http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2007-March/010392.html |title=whatwg Codecs (was Re: Apple Proposal for Timed Media Elements) |date=date|Mar 21 2007 |accessdate=2008-02-25 |mailinglist=whatwg mailing list |last=Stachowiak |first=Maciej] and Nokiacite conference | first = Stephan | last = Wenger | title = Web Architecture and Codec Considerations for Audio-Visual Services | booktitle = W3C Workshop on Video on the Web, December 12-13, 2007 | date = date|28 Nov 2007 | url = http://www.w3.org/2007/08/video/positions/Nokia.pdf | accessdate = 2008-02-25] had opposed the move. Opera Software and Mozilla have been advocates for including the Ogg formats into the HTML standard [ [http://www.pcworld.com/article/id,140408-pg,1/article.html PC World - Mozilla, Opera Want to Make Video on the Web Easier] ] [ [http://dev.opera.com/articles/view/a-call-for-video-on-the-web-opera-vid/ Opera ] ] and have included native decoding for these formats in their browsers.

On December 11, 2007, mention of the HTML 5 specification was updated replacing the reference to concrete formats with a placeholder: [ [http://html5.org/tools/web-apps-tracker?from=1142&to=1143 html5.org] ]

The removal of the Ogg formats from the spec has been criticized by some Web developers. [ [http://rudd-o.com/archives/2007/12/11/removal-of-ogg-vorbis-and-theora-from-html5-an-outrageous-disaster/ rudd-o.com] ] [ [http://delcorp.org/abbadingo/index.php/2007/12/12/removal-of-ogg-vorbis-and-theora-from-html5-an-outrageous-disaster Abbadingo » Blog » Removal of Ogg Vorbis and Theora from HTML5: an outrageous disaster] ] In response to such criticism, WHATWG has cited concerns from influential companies including Nokia and Apple over the Ogg formats still being within patent lifetime and thus vulnerable to unexpected future patent challenges. [cite mailing list |url= http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2007-December/013154.html |title=Re: whatwg Removal of Ogg is *preposterous* |date=date|11 Dec 2007 01:34:24 PST |accessdate=2008-02-25|mailinglist=whatwg mailing list |last=Hickson |first=Ian] A follow-up discussion also occurred on the W3C [http://www.w3.org/QA/2007/12/when_will_html_5_support_soone.html questions & answers blog] .

Background

On October 17, 2007, the W3C encouraged interested people to take part in a "Video on the Web Workshop", held on December 12, 2007 for two days. [cite web
url = http://www.w3.org/2007/08/video/
title = W3C Video on the Web Workshop
accessdate = 2008-06-14] A number of global companies were involved, submitting position papers. [http://www.w3.org/2007/08/video/positions/ position papers] Among them, Nokia's paper states that "a W3C-led standardization of a 'free' codec, or the active endorsement of proprietary technology such as Ogg … by W3C, is, in our opinion, not helpful." Whether Ogg is proprietary is debatable; while the formats are clearly open, they are designed and maintained by an international organization, Xiph.org. Ogg has followed a path similar to many other formats of the Internet age, such as PNG and GZip. While Xiph.org controls and defines the Ogg format specifications and their reference implementations, it does not own any patents and cannot control use of the formats, and the formats are thus not proprietary to Xiph.org.

Maciej Stachowiak — an Apple developer working on WebKit — described the reasons Apple had for opposing the recommendation, in an email message posted to the WHATWG mailing list:
* Other codecs offer significantly better compression than Theora; large-scale providers will prefer them to save bandwidth costs.
* Few — if any — hardware decoders are available for Theora. For mobile usage, software decoding is either unavailable or impractical due to power usage.
* It is theoretically possible for a submarine patent to exist, possibly waiting for a "deep pockets" (wealthy) company like Apple.Stachowiak also pointed out that the HTML specifications, traditionally, also failed to specify what referenced formats to use, leaving it to the market to decide.

There is agreement between the vendors that a "baseline" codec of some form is needed: a codec everyone will be able to access.cite mailing list |url=http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2007-March/010407.html |title=Re: whatwg Codecs (was Re: Apple Proposal for Timed Media Elements) |date=date|Mar 22 2007 |accessdate=2008-02-25 |mailinglist=whatwg mailing list |last=Lie |first=Håkon Wium | authorlink=Håkon Wium Lie] Besides Vorbis and Theora, H.261, H.264, AAC and MP3 were mentioned.cite mailing list |url=http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2007-December/013266.html |title=Re: whatwg Video codec requirements changed |date=date|Dec 11 2007 |accessdate=2008-02-25 |mailinglist=whatwg mailing list |last=Stachowiak |first=Maciej] The latter three are unacceptable to Opera and Mozilla on both practical and ideological grounds (cf: free software movement). Ogg Theora is unlikely to be accepted by Apple and Nokia, which leaves H.261 and Vorbis. Unlike Theora, Vorbis is already in use by multiple very large corporations,cite mailing list |url=http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2007-December/013274.html |title=Re: whatwg Video codec requirements changed |date=date|Dec 11 2007 |accessdate=2008-02-25 |mailinglist=whatwg mailing list |last=Parker |first=Conrad] and offers quality comparable to AAC. On December 12, 2007, Xiph.org published their official statement, objecting to some of the arguments against their codecs. [ [http://xiph.org/press/2007/w3c/ Xiph.Org's statement] ]

ee also

* Comparison of layout engines (HTML 5)
* Trident, used by Microsoft
* Gecko, used by Mozilla
* Presto, used by Opera
* WebKit, used by Apple, Nokia and Google Chrome

References

External links

* [http://www.whatwg.org/specs/web-apps/current-work/ WHATWG Current draft]
* [http://www.w3.org/html/wg/html5/ W3C Editor's draft]
* [http://www.w3.org/html/wg/html5/diff/ Differences from HTML 4]