[X3D-Public] HTML5 articles of interest from Government Computer News (GCN)
brutzman at nps.edu
Tue Oct 13 11:44:05 PDT 2009
HTML 5: What's new about it?
Precise elements and application programming interfaces
By Joab Jackson
Aug 28, 2009
HTML 5 will maintain backward compatibility with all former versions, while
cleaning up some ambiguities of the previous version of the markup language. It
will also offer a number of new elements, or markup symbols, that can more
precisely define the elements of a Web page. And for the first time, HTML will
come with a set of application programming interfaces (API) that assist
developers in setting up Web applications.
Here are some highlights:
* Article and Aside: Elements for marking the main body of text for a page
and for additional sidebars of text, respectively.
* Audio and Video: Elements for marking video and audio files. With these
elements in place, application authors can write their own interfaces or use a
browser's built-in functions for actions such as fast-forwarding or rewinding.
* Canvas: An element that can used for rendering dynamic bitmap graphics on
the fly, such as charts or games.
* Details: An element that could be put in place to allow users to obtain
additional information upon demand.
* Dialog: An element that defines written dialog on a Web page.
* Header and Footer: Elements for rendering headers and footers to a Web page.
* Meter: An element that can be used to render some form of measurement.
* Section: This element can be used to define different sections within a
* Nav: An element for aiding in navigation around a site.
* Progress: An element that can be used to represent completion of a task,
such as downloading file.
* Time: An element to represent time and/or a date.
* An API for allowing Web applications to run off-line.
* An API for crossdocument messaging, which allows two parts of a Web page
that come from different sources to communicate information.
* An API for dragging and dropping content across a Web page.
* An API for drawing 2-D images for the canvas tag.
* An API for playing audio and video, used in conjunction with the audio
and video tags.
Source: "HTML 5 differences from HTML 4" (
http://dev.w3.org/html5/html4-differences/ ) and HTML 5 Draft (
The long road to HTML 5
New version will bring the Web into the modern era—eventually
* By Joab Jackson
* Aug 31, 2009
When the White House decided earlier this summer to create a visual dashboard on
the USAspending.gov Web site, it used an obvious technology for the job: Adobe
Flash, which can render graphics and animations on Web pages.
The developers also are planning to use Microsoft Silverlight for future parts
of the service, too, according to a source. The choices make sense. Flash
players and, to a lesser extent, Silverlight are widely accessible by browsers
in the United States. But by using those technologies, the White House was
showing a preference for a single vendor's technologies, something government
agencies try to avoid. It looks too much like an endorsement and invites vendor
To be fair, Adobe has been open about Flash. The company published the Flash
specification on its Web site, and the underlying language, ActionScript, is
open source. But using Flash still relies largely on a single vendor's authoring
tool and player.
At the Government Web Managers Conference in Washington in April, federal Chief
Information Officer Vivek Kundra talked about how the government should use
standards where applicable to avoid issues of lock-in. However, he also noted
that Web managers can't always wait for the slow process of standards
development. USAspending.gov is a prime example of relying on what Kundra called
a de facto standard.
One reason is that the standardized, vendor-neutral language used to create the
Web, the Hypertext Markup Language, doesn't yet have the tools to create Rich
Internet Applications, such as dashboards.
The World Wide Web Consortium, the standards body behind HTML, ratified the
current version, HTML 4, in 1997. In the long interval since then, W3C has been
criticized for letting the Internet world jump ahead of the HTML standards. At
Crockford noted that a number of single-vendor offerings have sprung up because
of a lack of standards for offering rich Internet content. Microsoft Silverlight
and Adobe Flash are two of them.
W3C is working on HTML 5 to meet those new demands, promising that the new
version will offer the tools to build rich Internet applications without
requiring plug-ins from a vendor.
"The general goal of all of the work that we are doing on client-side browser
technologies is to provide developers and users with the choice of a common,
open Web platform based on completely open standards and with a feature set that
is on par with the set of features available from other application-delivery
platforms both on and off the Web," said Mike Smith, co-chairman of the W3C
working group that is drafting the new standard. HTML 5 will offer developers
the ability to draw graphics and create full-scale Web applications. HTML 5 also
will likely offer video and audio without plug-ins.
One might assume that the industry would move uniformly toward HTML 5, given
that the entire Web was built on the language. But that doesn't seem to be the
case. Microsoft and Adobe are contributing engineers to the HTML 5 standards
development process, yet both remain noncommittal about adopting HTML 5, at
least while it is still in development.
Work on HTML 5 started in 2004. W3C accepted a draft in 2007 and published a
first public working draft in January 2008. But even though it’s been around a
while, it still has a long way to go. "The HTML 5 timeline states that it will
be at least a decade before the evolving HTML 5 efforts are finalized, and it
remains to be seen what parts will be implemented consistently across all
browsers," said Dave McAllister, Adobe's director of standards and open source.
In the meantime, the developers recommend that government agencies experiment
with HTML 5 but not use it for production systems. They also want agencies to
send feedback to the W3C working groups.
To understand where HTML 5 needs to go, it is helpful to think about how we use
the Web. In 1997, much of what people did on the Web involved looking at Web
pages. There were some online services at the time, such as Amazon or eBay, but
most sites were static.
However, people are increasingly using Web applications, or services that
execute specific tasks on their behalf. For example, there are online
spreadsheets and word processors from Google and others. Those applications
require advanced functionality, such as the ability to save a Web application to
a local hard drive so users don't need to download it every time they need it.
And applications also need sophisticated controls, beyond the simple links that
Web applications have an extra level of interactivity, said Bruce Lawson,
standards evangelist at Opera Software ASA, maker of the Opera browser. The Web
experience is no longer just about "reading the text on the page and clicking on
the links. There is a lot going on there. HTML 4 is excellent at traditional
pages, but it is hard to write Web applications in HTML 4 because the language
wasn't designed for Web applications."
"HTML 5 tries to bring HTML into the world of application development," said
Vlad Vinogradsky, senior principal architect at Microsoft. The idea is to make
Sheets, an application development platform.
For instance, the canvas element of HTML 5 allows images to be rendered on a
browser rather than in the server, as is currently done. So if a user is
crunching data and would like to see a pie chart or graph, the canvas element
can display the chart without transmitting the information back to the server
for rendering. "Canvas allows you to carve out an area on the screen and start
painting it," Vinogradsky said.
In addition to the canvas function, HTML 5 offers a range of features for
building Web applications, such as the ability to save applications on a local
hard drive and support for more sophisticated navigation features.
HTML 5 also delves more deeply into the world of multimedia, such as video or
audio files. Its video tag will allow browser-makers to develop built-in media
Another big advance of HTML 5 is that will incorporate Extensible HTML, or
xHTML, a version of HTML that is rendered as a subset of an Extensible Markup
Language application. Casting HTML pages into an XML format allows their
contents to be parsed more thoroughly by computers. It will not be a requirement
that Web pages be rendered in strict XML syntax, which requires more diligence
on the part of the page authors, but pages that are rendered in such a format
will be machine-readable, Smith said.
The final call for changes in the HTML 5 specification is set for October,
although a lot of work remains after that.
In a way, the W3C working groups behind HTML 5 — the HTML Working Group and the
Web Hypertext Application Technology Working Group — are stuck between a rock
and a hard place. On one hand, they need to craft a standard that will cover all
possible uses of the Web. On the other hand, they need to keep up with the work
that Microsoft, Adobe and others are doing to extend the Web with their
individual technologies. In addition, HTML 5 should be backward-compatible,
meaning pages rendered in earlier versions of HTML will continue to work in new
HTML 5-ready browsers.
"It's a time-consuming process, and there is no way to short-circuit it without
also shortchanging the quality of the specification," Smith said.
Crafting a standard is an iterative process, he said. "Among the factors are the
issue of getting agreement from implementers and from the community about what
particular features to include, how to prioritize them, and what exactly the
precise specification text for those features should be," Smith said.
A draft must be written, then posted for feedback. Once feedback is in,
developers must alter it to address the valid points. The resulting changes must
be posted for further review. Developers also need to write test cases, which
can expose differences among the implementations.
Could development be broken into multiple chunks? It could, but it wouldn't
speed the process, Smith said. "A specification of this scale is inherently
complex to the degree that many parts of it are [intermingled] with one another
in such a way that it's very difficult to split them up into separate
stand-alone components without doing damage to the integrity of the
specification as a whole," he said.
In a recent blog post, Lawson described a number of issues that still need to be
worked out. One, for instance, is that some of the elements are ambiguously
defined. Although most of the new tags could be readily understood — the Header
and Footer tags, for instance, should be obvious to everyone — other tags, such
as the Aside tag, are open to interpretation.
"Everything is fine as long as everyone understands what the tag means, and they
use it all the same way,” Lawson wrote. “But if it is ambiguously defined, it
can be used in different ways, so there is no use of trying to mark something up
using an element if no one understands what the element is for."
Another hurdle is selecting the appropriate video format, or codec. The working
groups do not seem to be able to standardize on one. Some members are arguing
for the open-source Ogg Theora format, while others are opting for H.264. Google
has declined to use Ogg, citing bit-rate quality issues and the fact that the
Ogg format has not been entirely cleared of patent encumbrances. For its Safari
browser, Apple has opted for H.264, which can offer higher video quality but
costs money for browser companies to license. The W3C has made it a point not to
standardize on any technologies that must be licensed to use.
Another issue that federal agencies should keep in mind is that HTML 5 still has
a way to go in complying with Section 508 standards, which require agencies to
make information technology systems accessible to people with disabilities. The
W3C worked to make HTML 4 Section 508-compliant, but several of HTML 5’s
features, notably the video tag and the canvas element, don't have provisions
for providing alternate text for what they display, especially in cases where
they are displaying dynamically created content, Lawson said.
Despite those concerns, Lawson is optimistic that, when it does arrive, HTML 5
will be a success. "I'm pretty certain these things will be shaken out before
[HTML 5] goes live," Lawson said.
What should agencies do to prepare? Although they should keep an eye on HTML 5,
they should not be using it on production Web sites yet, Smith said. "No
organization should be using any new features from the HTML 5 draft with the
assumption that they are stable or supported across browsers," he said.
Indeed, browser support for HTML 5 varies. Version 8 of Internet Explorer, for
instance, implements certain HTML 5 features, such as DOM-based storage and
crossdocument messaging, which is the ability to build a customized Web page,
securely, from multiple data sources. Other browsers have implemented others
features. Firefox, Opera and Safari offer the canvas tag, for instance.
Vinogradsky said federal Web managers should "stay abreast with all the
developments and try to actively participate." If an agency has particular
requirements for the standards, being actively involved in the standards
development process is a good way to ensure that your needs will be addressed.
Lawson noted that unlike former iterations of the HTML development process,
anyone can join the HTML 5 working groups. Previously, only large organizations
could afford to sponsor a representative. The current working groups have
pledged to consider all valid input, no matter the source.
Will HTML 5 eliminate the need for technologies such as Silverlight or Flash?
Vinogradsky said no: Developers will use a mixture of both, weighing the
trade-offs of each technology. No matter how well-intentioned browser-makers
are, variances between how browsers render pages will always occur. A developer
has to weigh crossbrowser flexibility and the ability to use advanced features
supported by any one particular browser.\
"I think it is premature to jump into HTML 5, but it certainly is a technology
to watch," Vinogradsky said. "And you certainly need to have a voice in the
About the Author
Joab Jackson is the senior technology editor for Government Computer News.
all the best, Don
Don Brutzman Naval Postgraduate School, Code USW/Br brutzman at nps.edu
Watkins 270 MOVES Institute, Monterey CA 93943-5000 USA work +1.831.656.2149
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