Good question, I've just run into the same thing.
Someone please HELP!
same here .. wanted to test castor jdo with jboss but that link is not working
i am able to use castor jdo with jboss.
about the plugin available on the site,there is some thing wrong with the site. http://www.jboss.org/developers/projects/jboss/castor.jsp
you can build your castor plugin for jboss. pl. down load jboss3.x source . and compile it.
you can find the plugin source in "varia" in the top level of jboss's src directory.
compile this file and make a jar and place it in $JB_HOME/server/default/lib
" jar cvf castor-jboss-plugin.jar org/jboss/jdo/castor/CastorJDOImpl.class "
and about other config entries to deploy this. just follow the instructions @ http://www.jboss.org/developers/projects/jboss/castor.jsp
If you succeed in using it. one disappointmant you might get is that JBoss is not currently supporting Container/Bean ManagedTransactions for this when you use it from any session beans. (i haven't tried entity beans :-)
if you guys find any ways to manage transactions. pl .do update me ..