You could use CGI.pm for creating XML as it has nice feature that it will autogenerate HTML functions. Try this:

use CGI qw(:standard tag);

print tag({-type=>'invented', 'I made this up');
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Which will print

<TAG TYPE="invented">I made this up</TAG>
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... but is does have the disadvantage that it converts all tag names to upper case.

A quick check on CPAN also finds a module called XML::Generator which looks like it might do what you want.

How are you planning to deliver the XML to the browser? You should check out AxKit.