Avalon isn't about Web/GUI convergence

Edwin Khodabakchian echoes what seems to be a common -- but I think incorrect -- perception that XAML, the XUL-like layout language revealed this week to be a building block of Longhorn's Avalon presentation subsystem, heralds some kind of Web/GUI convergence:

We had prototypes and concepts at Netscape that were very close to what Microsoft is starting to promote with Avalon. One the positive side, it is great to see HTML, XML, CSS and SVG become the foundation of UI development within windows. [Organic BPEL]

My understanding, based on a demo I saw last week, is that although XAML is indeed an XML dialect, it has nothing to do with HTML, CSS, or SVG. It's true that the Avalon presentation engine is Web-like, or to be more precise ASP.NET-like in its separation of layout markup and "code-behind." But it builds no bridges to pre-Avalon clients. The foundation of Avalon's vector-based UI, for example, is Direct3D. I asked whether SVG -- an obviously relevant Web standard -- would be a preferred (or at least a supported) interface to Direct3D, and was told that it would not.

Here, from the newly-hatched Longhorn Developer Center, is another statement which implies a convergence that I don't see in the cards:

Avalon and XAML represent a departure from Windows-based application programming of the past. In many ways, designing your application's UI will be easier than it used to be and deploying it will be a snap. With a lightweight XAML markup for UI definition, Longhorn-based applications are the obvious next step in the convergence of the Web and desktop programming models, combining the best of both approaches. [Longhorn Developer Center: Code Name Avalon: Create Real Apps Using New Code and Markup Model]
To my way of thinking, you don't have "the best of both approaches" unless you have a ubiquitous client. As Jeremy Allaire pointed out the other day, Flash is making a serious effort along these lines, and has -- in Laszlo and the forthcoming Royale -- its own XML-based layout techniques. I've also mentioned Mozilla's cross-platform technique, XUL. Now Microsoft is pitching a Windows-only UI renderer that targets 2006-era desktops and notebooks, while allowing MSIE to stagnate. I can see how and why they arrived at this strategy, but it doesn't seem to be the kind of Web/GUI convergence I'm looking for.

Former URL: http://weblog.infoworld.com/udell/2003/10/28.html#a833