use strict;
use warnings;
use XML::LibXML;

my $ns = 'http://www.example.com';

my $doc =  XML::LibXML::Document->new;
$doc->setDocumentElement($doc->createElementNS($ns, 'q:one'));
$doc->documentElement->appendChild($doc->createElementNS($ns, 'q:two'));
$doc->documentElement->appendChild($doc->createElementNS($ns, 'q:three'));
warn $doc->toString(1);