It was written by Michael O'Keefe from Cork, who I used to know although i haven't met him in a long while. He's a schoolteacher and I think he used to present a music programme on Kilkenny local radio. "We're glad you passed this way", Roisin is a reference to a poem that Luke wrote "For what died the sons of Roisin...was it greed?". It's on some Dubliners album.