I've begun to dread every time I see a blog entry in my aggregator with "XAML" in the title. It usually means I am either going to read a lot of inane fanboy gushing about the latest and greatest from Microsoft or some FUD from some contingent that either misunderstands the technology or has an axe to grind with Microsoft. So much so, I've been contemplating adding a "hide entry if contains keyword" feature to RSS Bandit so I never have to read another post about XAML. Anyway, back to the point of my post.
Diego Doval has an entry entitled XAML and... Swing which contained a number of opinions that completely perplexed me. I'll go over each one in turn.
XAML will be Windows-only, so in that sense the comparison is stretched. But this is a matter of practice, in theory an XML-based language could be made portable (when there's a will there's a way). XAML was compared a lot to Mozilla's XUL, and rightly so, but I think there are some parallels between it and Swing as well.
In theory, every language targetted at a computer is portable to other platforms. However if I wrap XML tags around C++ code that uses Win32 API calls, how portable is that in practice? As for parallels between XAML and Swing, I thought this was extremely obvious. XAML is the XML-ized way to write what one could consider to be the next generation WinForms (managed APIs for interacting with Windows GUI components) applications. In fact, someone has already implemented XAML for WinForms, called Xamlon. Considering that Swing (Java APIs for interacting with operating system GUI components) is analogous to Winforms it isn't a leap to see a parallel to XAML and Swing.
One big difference that XAML will have, for sure, is that it will have a nice UI designer, something that Swing still lacks. On the other hand, I think that whatever code an automated designer generates will be horribly bloated. And who will be able to write XAML by hand?
One of the chief points of XAML being an XML-based markup language is so that peple can actually author it. My personal opinion is that this is more of a bad thing than a good thing, I prefer using GUI tools to design a user interface than dicking around with markup files. I've always disliked technologies like CSS and ASP.NET, moving GUI programming in that direction seems to me like a step backwards but based on the enthusiasm about XAML showed by various people in the developer community it seems I am a Luddite.
The main thing I want to point out about the Diego's statements so far are that they are FUD, no designer has been demoed for XAML let alone one that generates bloated code. This is all just negative speculation but let's go on...
And: the problem of "bytecode protection" in Java comes back with XAML, but with a vengeance. How will the code be protected? Obfuscation of XML code? Really? How would it be validated then? And why hasn't anyone talked about this.
XAML is compiled to IL. XAML obsfucation questions are IL obfuscation questions. If you're gung ho about protecting your "valuable IP" with IL obsfucation technologies then grab a copy of Dotfuscator or Spices.NET.
On a related note, Robert says this regarding XAML:
[...] you will see some business build two sites: one in HTML and one in XAML. Why? Because they'll be able to offer their customers experiences that are impossible to deliver in HTML.
Come on, Robert, these days, when everyone's resources are stretched to the limit, when CIOs want to squeeze every possible drop of code from their people, when everyone works 60-hour weeks as a matter of common practice, are you seriously saying that companies will have two teams to develop a single website? Is this Microsoft's selling point? "Here, just retrain all of your people, and double the size and expense of your development team, and you'll be fine."
I tend to agree with Diego here. Having a XAML-based website on the Internet will most likely be cost ineffective for quite a while. On the other hand, it is quite likely that using XAML on the intranet will not be. Corproate intranets are all about homogenous environements which is why you tend to see more Java applets, IE-specific pages and ActiveX controls used within intranets than on the global World Wide Web. If I was a member of the Longhorn evangelization team or any other of the public faces of Longhorn or Avalon I wouldn't focus much on XAML on the World Wide Web but that's just my opinion.
That leaves two possibilities: 1) XAML will be niche and never really used a lot (think ActiveX, or, hey, even Java Applets!) or 2) XAML will kill HTML.
Talk about completely missing the point. XAML is primarily for writing Windows client applications, y'know like RSS Bandit or SharpReader, not for delivering stuff on the Web. I don't think anyone at Microsoft is silly enough to think that XAML will replace HTML. The idea is completely laughable.
It is always amazing seeing how stupid and arrogant people tend to think Microsoft is.