The "stable version" is in the oacs-5-3 branch
cvs -d:pserver:anonymous@cvs.openacs.org:/cvsroot checkout -r oacs-5-3 openacs-4/packages/xotcl-core
cvs -d:pserver:anonymous@cvs.openacs.org:/cvsroot checkout -r oacs-5-3 openacs-4/packages/xowiki
You should get these versions as well from "install/update from repository" from /acs-admin/install/
To get the best version of XOTcl (the Tcl extension), check out http://www.xotcl.org