Ben,
you should be able to install it from
http://media.wu-wien.ac.at/download/xotcl-core-0.30.apm
http://media.wu-wien.ac.at/download/xowiki-0.17.apm
from from server via /acs-admin/apm/package-load, provided that you have xotcl akready installed.
i have no idea how openacs.org/repository works, but this would be certainly a more convenient approach from upgrading packages for non-programmers. an alternative approach would be t allow access to the cvs repository via a oacs-web interface.
