To get your feet wet, start with a basic XHTML tutorial if you haven't already. This won't show you the real value of XML (it's pretty much just a somewhat stricter form of HTML), but it will be quick reading and will get you a basic feel for the syntax of XML. After that, if you want to understand the benefits of XML over other markup languages like HTML, you'll need to read up on XML namespaces, XSL, and possibly XSLT. If you're serious about applying it to WAP, you then may also need to dig into RDF (though this is somewhat stiffer materiel than the preceding). The same w3schools website has tutorials on most of these things too, and most of them are light enough that you can read one in an hour or three, depending on how quickly you read. There are also various other XML-related things that you may or may not care about, depending on what you're doing -- XPath, XPointer, XML Schema (err, Schemata), and so on and so forth. Don't worry about learning all of these up front; some of them you may not need for a while if ever. Just learn the basics (XML and namespaces) and whatever other bits you need for your particular application.

If all you want to see are examples of XML in action, check out Mozilla (which uses it for its XUL widget sets and themes) and OpenOffice (which uses it for its file formats, among other things -- very handy, as it makes it easy for other apps to work with the files). XML is not the solution to all problems, but it IS useful.

$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,".rekcah lreP rehtona tsuJ";$\=$ ;->();print$/
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