AJ's blog

March 12, 2011

HTML5 – Part III: The Limits

Filed under: HTML5, Silverlight, Software Architecture — ajdotnet @ 5:26 pm

Alternative title: HTML5 – Still HTML, not a RIA platform

The last post was about the chances and benefits of HTML5. But there are also some exaggerated expectations that HTML5 cannot fulfill. Mainly this concerns the term “RIA”, and the effect HTML5 will have in this area.

Or as someone wrote:

“Will HTML 5 one day make Flash, Silverlight and other plug-in technologies obsolete?” (link)

Actually this is a very regular question I have to answer. (Often enough it doesn’t come as question, but as statement. Or accusation. Sic!)

I already detailed how HTML5’s video and canvas will take over tasks that have formerly been solved by other technologies, namely Flash. And some people seem to infer that if Flash is a RIA technology, and HTML5 obsoletes Flash, then HTML5 must obviously make RIA technologies obsolete in general.

Quite wrong. Actually the fact that Flash is used for video and 2D graphics has nothing to do with Flash being a RIA technology. Flash simply happened to be able to delivering these features, both in terms of technical capability as well as broad availability. That it also happens to be a RIA technology is more or less happenstance.

But before moving on we need to clarify the terms “RIA” and “RIA technology”…

My personal definition of RIA technologies relates to the following attributes: Stateful programming model, with some kind of page model, for applications running in a browser sandbox. This includes Flash, JavaFx, Silverlight as a browser plugin (but not in its WP7-platform variation).

Wikipedia applies the terms to Flash, Java (not JavaFx! Sic!), and Silverlight. Sill, this is debatable, and a year ago even Wikipedia had a far broader definition, but in my experience this actually covers the common understanding. Curiously Adobe claims that AIR is their RIA technology, not Flash. But me, Wikipedia, and general consensus agree that Flash indeed is a valid RIA technology.

By the way: Leaving HTML+AJAX out of this picture is by no means meant to be deprecatory, it just reflects common understanding. Wikipedia actually makes the distinction based on the (lack of) necessity to install an additional software framework.

And a final tidbit: Once upon a time Microsoft advertised Silverlight as Flash replacement, addressing video and graphics, just like in the typical Flash use cases. However, even with growing adoption of the Silverlight plugin, Silverlight never became a serious competitor for Flash in that area. (This may actually have played a role in Microsoft’s commitment to HTML5…) Still, Silverlight has long outgrown this narrow definition and later versions has put more emphasis on business features.

So, let’s have a look at where HTML5 reaches its limits and where RIA technologies might kick in. I’ll look at regular web applications before moving on to RIA applications.

Web Applications

HTML5 is going to address standard demands of web applications, including those addressed today by Flash. This will have a crowding-out effect on Flash and RIA technologies in general. But once the demands go beyond being “standard”, RIA technologies will find their niche even in web applications.

On example could be premium video delivery: Some vendors will probably be eager to offer unique selling propositions in the emerging markets of WebTV and high quality HD video content (probably involving DRM).

Since Flash can no longer play the trump of being the only or the broadest available platform in this area, this will also change the picture among the RIA technologies. Especially Silverlight has been very successful in this area recently. Take the Olympic Games or maxdome.

Other examples include complex user interactions that are not feasible with canvas and script, e.g. Mazda’s car configurator, and similarly dynamic data visualizations.

Finally there is the support of additional features. RIA technology vendors certainly have shorter innovation cycles than standards bodies. This especially includes hardware support (camera, game controller, hardware accelerated animations and 3D).

These scenarios all require the user to accept the plugin – which might become a more severe issue if this necessity is less ubiquitous. Thus for the web site provider this always incurs the question whether he can compel his users to use his offering despite that nuisance, or whether he may have to provide a (perhaps simplified and less capable) HTML based version.

RIA Applications

HTML5 won’t turn HTML into a RIA technology. It doesn’t come with a new programming model, doesn’t change server side processing, page model, and postbacks, doesn’t change that fact that the HTML ecosystem really is a conglomerate of diverse technologies.

Many applications – be it multimedia, some kind of hardware dependency, or line of business – simply require the potential of rich client applications. For these, HTML simply cannot deliver what is necessary. Typical demands include:

  • Data centric applications: Large amounts of data; data input with complex validations, lists with extended feature sets, …
  • Usability: Immediate feedback (not possible with postbacks), dynamic UIs with forms built dynamically or changing depending on user input, …
  • Business features: Printing, graphical presentation, Office integration, …
  • Offline capability…
  • Connectivity: Communication patterns such as peer-to-peer, server pushes, …
  • Multimedia and hardware support: Animations, camera, microphone, multitouch, …
  • Rich platform: Stateful programming model, component model, feature rich controls, rich databinding capabilities, …

While these are certainly not the demands for typical web applications. But intranet applications and applications addressing some distinct or closed user group on the web are very well within this category. Prominent example is SAP, one can also think of WebTV portals, home banking, or other.

In the past java applets were often used to cover these demands. Recently AJAX approach have spread, but while this worked to some degree, it often falls short of meeting the demands completely. From a technical perspective, RIA technologies are the adequate choice in these scenarios. And (in my opinion), Microsoft Silverlight is currently the best technology available in that area. Adobe AIR lacks availability and adoption, Flash alone is not sufficient, and JavaFx seems to die a slow death


HTML5 will push RIA technologies out of their makeshift role (video and canvas). However this doesn’t affect the feasibility of employing RIA technologies on their own turf, i.e. beyond-HTML-capability demands in web applications and fully fledged RIA applications.

However, since this “pushing out of RIA technologies” mainly affects Flash, HTML5 has an interesting effect on the RIA market: Broad availability is no longer a strong USP for Flash, which is to the benefit of Silverlight. Add the hazy prospect of JavaFx and the fact that Silverlight is not only a RIA platform, but also enters devices (WP7, WebTV), and HTML5 may actually further the adoption of Silverlight – not as cross-platform tool, as it was once intended, but in all areas not covered by HTML5.

The one argument in favor of HTML5 – which no RIA technology is likely to ever achieve – is its universal availability across all platforms, even if that comes at a cost.

Where are we?

The conclusion of this little series may be as follows: The conflict, or enmity, between HTML5 and RIA that some people see (or exaggerate) doesn’t really exist. There may be a competition between HTML5 and Flash, but even that may turn out differently form what people expect.

Actually HTML5 and RIA complement each other. There are areas in which one technology certainly make more sense than the other, other areas in which there is a choice, again other areas in which a combination of both may work best; even areas in which neither is an ideal choice. E.g.…

  • A web application addressing the broadest available audience? HTML5.
  • An LOB application with high usability demands? Silverlight.
  • A mobile application addressing a broad audience? HTML5. As long as not tighter device integration is necessary, in which case one has to address several mobile OSes…

And between these black-and-white examples there’s a lot gray areas, to be decided on a case-by-case basis. And usually the important thing is not exactly which technology you favor. The important thing is to make an informed decision, aware of the pros and cons, and not solely based on political opinions of certain apologists.

That’s all for now folks,

kick it on DotNetKicks.com


1 Comment »

  1. I’m not sure i could count out HTML5 for LOB applications but you do make some very interesting points.

    1 correction if I may.

    HTML5 can give very tight compatibility with device hardware with tools like AppMobi and PhoneGap. Since I wouldn’t build a smart phone app without a 3rd party tool then for me to exclude them would make my opinion academic rather than practical.

    So I agree with much of what you said except for this point.

    Thanks for writing this blog…

    Comment by Bob — March 16, 2011 @ 1:41 pm

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