The XUL News Wire reports that Macromedia has just released their very own XUL dialect for a beefed up Flash player (formerly known as Royale now known as Flex) that runs outside a browser and lets you build "classic" standalone desktop apps using XML.

In the tech paper titled "An Overview of MXML, the Macromedia Flex Markup Language" Macromedia Flex Evangelist Christophe Coenraets writes:

Markup languages have proven successful and relatively easy at laying out application user interfaces. MXML, the XML-based markup language introduced with Flex, builds on this success. You use MXML, much like HTML, to declaratively lay out the user interface of your application. As an XML-based markup language, MXML has a more structured and less ambiguous syntax than HTML. MXML also includes a much richer set of tags than HTML. For example, DataGrid, Tree, TabNavigator, Accordion, and Menu are all part of the standard set of tags. You can also extend the MXML tags and create your own components. But the most significant difference is that MXML-defined user interfaces are rendered by Flash Player, providing the users with a much more engaging experience than traditional HTML-based, page-centric web applications.

In addition to laying out visual components, you can also use MXML to define other important aspects of your applications: For example, you can declaratively define your application as a client for a web service, or define animations that provide the user with visual cues about the state transitions in your application.

Now if you wonder what Macromedia XUL (aka MXML) looks like here's a sampling:

<mx:Application xmlns:mx="http://www.macromedia.com/2003/mxml">

    <mx:TextInput id="source" width="100"/>
    <mx:Button label="Copy" click="destination.text=source.text"/>
    <mx:TextInput id="destination" width="100"/>

</mx:Application>

Deja vu? How about this one:

<mx:Application xmlns:mx="http://www.macromedia.com/2003/mxml">

    <mx:HBox>
      <mx:Tree/>
        <mx:VBox>
            <mx:DataGrid/>
            <mx:TextArea/>
        </mx:VBox>
    </mx:HBox>

</mx:Application>

Now to wrap up the MSXML story guess what you use for styling? Allow me to quote Christophe Coenraets:

Flex adopted the cascading style sheet (CSS) standard to help ensure the consistency of your user interface and to facilitate the maintenance of your applications. Much like in HTML, you can inline a style sheet in your code, point to an external style sheet, or define a style as an attribute of a specific element. Style sheets also allow you to define fonts for your applications. The required font definition is embedded in the bytecode of your application to ensure that the font is rendered correctly even if it is not available on a user's machine.