Less is written about Richard Proulx, such as his actual birth date or information about a memorial service.
I count him among Catholic composers since he served Holy Name Cathedral in Chicago from 1980 to 1994 and founded the Cathedral Singers in 1991. He also served St. Thomas (Episcopal) in Medina, WA, as well as Temple Hirsch Sinai in Seattle.
He has served as a consultant for such hymnals as The Hymnal 1982, New Yale Hymnal, the Methodist Hymnal, Worship II & III, and has contributions in the Mennonite Hymnal and the Presbyterian Hymnal.
I have less personal knowledge of this composer, so check out this tribute video for more info.
UPDATE: I thought my favorite Proulx composition is "Canticle of the Turning." He had nothing to do with it! Credit goes to Chris of LutheranKantor.com for the correction. Here are the corrected details on the work.
Text and tune are by Rory Cooney. This is a versification of the Magnificat. Honestly, here, I am not sure the prose text of the Magnificat is captured as well here as the Calvinist tradition of setting Scripture to meter might have done. None the less, I think my Irish Protestant Grandmother from the Holiness tradition would probably have liked this one!
If I were to use this in the Divine Service (or at Evening Prayer in place of the Magnificat) I would probably place it during the Advent season. The anticipation of Advent is captured with the repeated line, "...the world is about to turn."
Meanwhile, getting back to Richard Proulx, here is the Sanctus, the "Great Mystery of our Faith," "Amen," and Agnus Dei from his Mass for the City. Youtube, don't fail me now!!!