See Simpler than XML::Simple

If you have XML::Simple, you most likely also have XML::Parser & XML::Parser::Expat. XML::Rules is a plain Perl module on top of XML::Parser::Expat, so you don't really need to build and install it into the Perl directories, you can use it as a module you write yourself and copy it with the rest of your app/scripts.

I believe you can do the same with XML::Twig.