Potential conflicts and overlap between the first update to HTML (http://www.w3.org/html/wg/html5/) in a decade by the World Wide Web Consortium (W3C (http://www.w3.org/)) and XHTML has been addressed by the standards body.

The group, meanwhile, has also acknowledged vendors are - once again - pushing their own platform-specific technologies, this time on RIA, with the standards process unable to keep up. This poses a problem on interoperability.

A W3C working group editor's draft paper has said (http://www.w3.org/html/wg/html5/#relationship0) that HTML 5 deals with a "different" set of problems than XHTML V2 (http://www.w3.org/TR/xhtml2/).

A detailed comparison (http://www.ibm.com/developerworks/web/library/x-html5xhtml2.html?S_TACT=105AGX08&S_CMP=EDU) highlights these differences and suggests that the two standards will appeal to different sets of developers.

There has been concern, voiced by Reg readers (http://www.regdeveloper.co.uk/2008/01/22/html_five_preview/comments/) at least, that the W3C is layering on multiple standards, creating confusion over what standards and technologies to use.

The W3C has also moved to position HTML 5 in relation to proprietary UI languages from Adobe, Microsoft and Mozilla - namely, Flash (http://www.adobe.com/products/flashplayer/), Silverlight (http://silverlight.net/) and XUL (http://www.mozilla.org/projects/xul/). The editor's draft said HTML is limited to providing a semantic-level markup language and associated semantic-level scripting APIs.

It's also an open language without risk of proprietary lock in.

"For sophisticated cross-platform applications, there already exist several proprietary solutions (such as Mozilla's XUL, Adobe's Flash, or Microsoft's Silverlight)," the group said.

It also appeared to acknowledge the vendors pushing their own, platform-specific rich internet application technologies faster than the standards process can keep up. It noted the complexity challenges of interoperability. We've seen a similar pattern of activity before, more recently on web services where - for example - Microsoft and IBM set the agenda on WS-* and repeated W3C-based work led by IBM and Sun Microsystems.

"These solutions are evolving faster than any standards process could follow, and the requirements are evolving even faster. These systems are also significantly more complicated to specify, and are orders of magnitude more difficult to achieve interoperability with, than the solutions described in this document," the latest W3C draft said.

"Platform-specific solutions for such sophisticated applications (for example the MacOS X Core APIs) are even further ahead."

Interestingly, Microsoft, Mozilla and Apple have participants on the HTML5 working group, but Adobe is absent.

Of possibly greater concern is the time it will take for the massive HTML 5 specification to be refined and implemented. In a recent SD Times interview (http://www.sdtimes.com/content/article.aspx?ArticleID=32067) Chris Wilson, Microsoft's Internet Explorer architect, suggested that HTML 5 should be split into more manageable pieces and progressed by several teams working in parallel.

HTML 5 aims to make life easier for web developers by providing native support for the type of features associated with advanced web applications. It includes a wider range of interactive components that could reduce the amount of JavaScript coding. It could also reduce the need for asynchronous JavaScript plus XML (AJAX) mechanisms for network communication and server interaction.

One of the main improvements over previous versions of HTML is the inclusion of multimedia features and a recognition that future web applications could be accessed from mobile devices. The importance of this was emphasized this week when Trolltech revealed that it had built HTML 5 audio and video support (http://people.w3.org/mike/planet/html5/) into its QtWebkit development tool.®

Additional reporting by Gavin Clarke

Related stories

JavaFX preview highlights critical weaknesses (21 August 2008)
http://www.theregister.co.uk/2008/08/21/javafx_preview_review/
JavaScript standards wrangle swings Microsoft's way (15 August 2008)
http://www.theregister.co.uk/2008/08/15/adobe_microsoft_ecma_javascript/
Nokia's Trolltech renews Windows mobile vows (6 August 2008)
http://www.theregister.co.uk/2008/08/06/trolltech_windows/
Rich data: the dark side to Web 2.0 applications (1 August 2008)
http://www.theregister.co.uk/2008/08/01/rich_data_vulnerabilities/
Consume .NET services without Silverlight (17 July 2008)
http://www.theregister.co.uk/2008/07/17/flex_gets_soapy/
Sun's JavaFX must toolup against Adobe - pronto (14 July 2008)
http://www.theregister.co.uk/2008/07/14/javafx_review_part_two/
Adobe boosts Flash media search with Google and Yahoo! (1 July 2008)
http://www.theregister.co.uk/2008/07/01/adobe_flash_google_search/
Sun to lose lunch money on JavaFX (12 June 2008)
http://www.theregister.co.uk/2008/06/12/javafx_review_part_one/
Microsoft: keep your sticky mitts off our language runtime (12 June 2008)
http://www.theregister.co.uk/2008/06/12/microsoft_dlr_closed/
AJAX browser wishlist call goes unanswered (10 June 2008)
http://www.theregister.co.uk/2008/06/10/ajax_alliance_poll_apathy/
Silverlight 2 beta 2 - Go Live if you dare (9 June 2008)
http://www.theregister.co.uk/2008/06/09/silverlight_2_beta_2_review/
Windows veteran jumps to second Silverlight (4 June 2008)
http://www.theregister.co.uk/2008/06/04/infragistics_silverlight/
Gates' last act: frees IE 8 and Silverlight second betas (3 June 2008)
http://www.theregister.co.uk/2008/06/03/gates_silverlight_ie/
Mozilla Screaming Monkey offers freedom from IE 'millstone' (29 May 2008)
http://www.theregister.co.uk/2008/05/29/screaming_monkey_ie/
Microsoft urges developers to tag sites for IE8 (27 May 2008)
http://www.theregister.co.uk/2008/05/27/ie8_fall_beta/
Google gears Java 5 Web Toolkit (27 May 2008)
http://www.theregister.co.uk/2008/05/27/gwt_one_five_roadmap/
Windows XP bests OS X in RIA test on Intel (23 May 2008)
http://www.theregister.co.uk/2008/05/23/ria_benchmarks/
'Major' Flash Player beta released (15 May 2008)
http://www.theregister.co.uk/2008/05/15/flash_player_10_beta/
Back to the future: the Java client’s second go-round (12 May 2008)
http://www.theregister.co.uk/2008/05/12/javaone_outing/
Live Mesh: Hailstorm take 2? (9 May 2008)
http://www.channelregister.co.uk/2008/05/09/live_mesh_hailstorm/
Adobe lifts Flash and AIR development restrictions (1 May 2008)
http://www.theregister.co.uk/2008/05/01/adobe_open_access_protocols/
Adobe launches 'free' Flash-only media player (9 April 2008)
http://www.channelregister.co.uk/2008/04/09/adobe_media_player/
Cross industry AJAX group reaches IE 8 'consensus' (28 March 2008)
http://www.theregister.co.uk/2008/03/28/openajax_alliance_internet_explorer_eight/
Open AJAX frameworks not fit for 'power users' (28 March 2008)
http://www.theregister.co.uk/2008/03/28/ajax_analyst_reversal/
Silverlight 2.0 data and web services explained (6 March 2008)
http://www.theregister.co.uk/2008/03/06/silverlight_two_data_services/
Microsoft plays IE 8 interoperability pick and mix (6 March 2008)
http://www.theregister.co.uk/2008/03/06/ie8_standards_roadmap/
Microsoft jump starts IE 8 with community push (5 March 2008)
http://www.theregister.co.uk/2008/03/05/ie8_standards_support/
Time to balance WS-* and REST (25 February 2008)
http://www.theregister.co.uk/2008/02/25/ws_versus_rest/
Just how cute are cats? W3C can help (25 January 2008)
http://www.theregister.co.uk/2008/01/25/html_5_em/
Major HTML update unveiled (22 January 2008)
http://www.theregister.co.uk/2008/01/22/html_five_preview/
W3C sets standards for SOA and Web 2.0 (17 September 2007)
http://www.theregister.co.uk/2007/09/17/grddl_web_services_policy/