I think the best/most usable solution for you would be to get a MySQL dump of the node table. This circumvents all the XML trickery and other problems that arise from the transfer to and from XML. If you are really keen on getting XML, g0n maintains an XML mirror of most newer nodes.

Perlmonks is "based" on the Everything Engine but the developments have diverged into different directions and the two engines are basically incompatible, so I'm not sure that nodeballs could be enabled here easily.