However from a Perl programmers perspective, you don't need to use an external standalone XSL-T engine such as Saxon, or Xalan (good though they both are). You can get your own application to do it it's self, directly or via a library, this is how Cocoon and AxKit and many other commercial systems do.

From the perspective of a Perl user you can use Matts excellent AxKit framework, or his XML::LibXSLT module directly from within your Perl code. I use XML::LibXML to manipulate XML files, template them with XSL-T, and save the output as HTML files! See Mega XSLT Batch job - best approach?, (in answer to Tilly's question, in testing on a 1Ghz Linux box, from one 1Mb XML file I was able to create over 2000 HTML pages, and associated folders in under 30 seconds!)

If used right XML is a very good tool, just remember it's not right for everything, no matter what some people say!

Another humble 2p

Don't get me wrong...but all of what you mentioned can be done from flat-files...heck, even I wrote a script that allows me to multi-template & table my data from flat files (without the bulk of additional record and field tags). This is really only a concern when dealing with large data sources. The XML markup is a p.i.t.a. and incrediblely redundant.

I'll check the page on Saxon out...no guarentees that I'll convert though.

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Sean Shrum
http://www.shrum.net

You can take tabulated data, and using one of many templating system you can generate something else from it. This works perfectly well, for many applications.

If your source file is an XML file, you can have any kind of XML file you want, you can even verify it against an XML Schema or DTD (take your pick) should you want to.

You can make a range of XSL-Templates to convert the XML file you have into another XML file. The Transformation always gives you a well-formed new XML (or XHTML) file. You can have a range of XSL-Templates for a range of devices, web browser, WAP phone, another server. If you want you can also use XSL-FO and generate a PDF file should you wish.

Should you want you can pipeline one XML document into one round of templating after another, as each step always generated well-formed XML.

XML, XSL-T, XSL-FO, DTD, XML-Schemas are all public standards, you can use a range of tools, on different operating systems, in different languages, and most of the time things behave the way you expect them to. Using one XML file and one XSL-template I can generate one HTML file on my Linux box and NT box, using Saxon, Xalan, LibXSLT or even MS-XML, it's pretty predictable.

One of the key strengths of XML is that the coding and the content/templates are kept apart. By using XML, you can use any code you want, and any content and it works! As your team gets bigger it means that the coders code and the mark-up people mark-up.

There is a good thread on templating versus XSL-T here: XSLT vs Templating? where people put many sound arguments for both sides. Matts in particular as a strong advocate of XML says many things that I could add here.

I'm not saying that XML is the best solution, just that it's one solution, and for larger more complex applications, it's focus on flexible structures, and it's wide scale use, does make it the tool of choice.

Update: Typos fixed, and XSLT link added