DubMed has migrated to a better server. Its database is now mySql and php3 does the metadata linking instead of corba (now gone). see cvsweb [1] for the code, and the project page [2] for more info.
Links:
[1] http://oldap.med.yale.edu/cgi-bin/cvsweb.cgi
[2] http://oss4lib.org/projects/dubmed.html