Informal liturgies have blossomed in the post-conciliar Church Featuring prayers of great immediacy, sensitivity, and beauty, these liturgies give voice to the vital . growing heart of belief, and nurture the Christian unity of the participants to an extent hardly dreamed of a decade ago. The Experimental Liturgy Book, the most comprehensive collection of its kind, presents a carefully selected cross section of more than 100 such informal liturgical prayers. The first part of the book contains variants from the confiteor, gloria, creed, offertory, eucharistic prayer, breaking of the bread, communion prayers, final blessing, and dismissal. The second part includes eleven complete masses written to fit the needs of particular congregations and special occasions. Designed according tho the traditional structure of the Roman Rite Mass, these variations show how it can be made flexible and open to occasional celebrations without breaking with the liturgical heritage of the Western Church. Part Three contains communal penance service designed to stress both individual and social aspects of relationship to God. All prayer are arranged in sense lines for dialogue recitation. Robert Hoey, former chaplain of Boston College, is an experienced student of experimental liturgies. His popular 'Faber House Liturgy, printed for use on the Boston College campus, was the genesis of The Experimental Liturgy Book.