Father Thomas Keating was known throughout the world as an exponent, teacher, and writer on contemplative prayer. A Cistercian (Trappist) monk of St. Benedict's Monastery, Snowmass, Colorado, he was a founder of the Centering Prayer Movement and of Contemplative Outreach. He authored numerous books, particularly of the trilogy Open Mind, Open Heart; Invitation to Love; and The Mystery of Christ. Among his books is The Daily Reader for Contemplative Living, compiled by S. Stephanie Iachetta.
Gustave Reininger is a founder and for many years a trustee of Contemplative Outreach, an ecumenical network that teachers Centering Prayer in churches, schools, and places of work.