In both the case of XML::Simple and XML::Parser, these only deal with the input of XML into your program; you'd still need another module that deals with the output such as XML::AutoWriter; thus your input and output methods may seem very disjointed. While I've not used Xerces, it easy to see that it handles both sides of XML (parsing and generating). The only thing that is of concern is that it is a perl module that sits on top of a C/C++ library; thus, some of the function calling seems to get hairy, and there might be some performance penalties. Xerces appears to be very well documented by the Apache team (I've yet to see anything Apache puts out that's poorly documented), so you'll find just as much info about Xerces as you would with XML::Simple or ::Parser.

I'd say the best thing to do is to try to write some quick sample application code using both, and decide which one feels 'best' to work with, with all other factors being equal; consider expandibility, code maintainence, and how others may seem the code as part of your decision.

---

Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain