As already mentioned XML isn't a layout system. XML is a markup language that is relativly easy to manipulate with Perl (or any other modern language) and it's easy to convert to other XML and non XML formats via XSLT.

XML is buzz word compliant, but don't let that put you off, it is a great format to use and Perl has the tools to do the work. With XML you get a nice public standard, so you get lots of documentation both on and off line. While it's verbose, you can read and edit it by hand with a simple text editor - though I would recommend a proper XML editor. My favourite is the XSLT language, while it seems a bit wiered at first it's very powerful, and well documnented too.

I'd start by looking at XML::LibXML and XML::LibXSLT these are great modules, giving you a powerful XML parser and very fast XSLT processor. Both are well written and based on the excellent and very fast The XML C library for Gnome. Don't think that XSLT is slow, while it's true that the first processors were slow with poor standards support the picture has improved, and it can be done on the fly without big-iron.

Depending on how sophisticated you want to go, I'd also take a look at the excellent AxKit XML publising suite for Apache. It's based on the LibXML and LibXSLT modules, but adds sophistication and Apache integration as well.

XSLT can easily handle common XML output forms such as XHTML or RSS/RDF, plain text formats such as CSV/TSV, and produce XSL-FO for conversion to PDF. It may be overkill for your project, but it is a pretty sophisticated set of technologies.

Good luck!

Currently, the buzzword compliance police state that you should obviously use XML -- but as always it depends on what you need to model.

If the data is simple, XML may be overkill -- but if want to present via web browsers then XML and XSLT may be the way to go.

I built a system where I work now that separates format from processing. We use it for exports, imports, reports, etc. But it doesn't have at its core any existing format. Instead, it maps inputs to a commom row-oriented object format, provides ways to plug in filters against those objects as they "flow" through a transform, then allows any number of formatting outputs to be placed on the other end.

Also realize the HTML, XML, etc. are all based on a broader specification known as SGML. At one job there was a movement to specify everything in SGML as a common format. I've never really been convinced of that approach though. Standards change all the time and today's pick may look lousy in a year or two. I much prefer to build flexible systems that allow things to be pulled in and out with ease, and while keeping most clients insulated from the underlying changes.