This is the download site for non EPL'ed Buckminster plug-ins Choose one of the following URL's for the p2 update site manager (or director app):

http://download.cloudsmith.com/buckminster/external-4.4 (Luna)
http://download.cloudsmith.com/buckminster/external-4.3 (Kepler)
http://download.cloudsmith.com/buckminster/external-4.2 (Juno)