Free-culture and free software advocates easily identify art and technology as fields of interest. Software to share creates common tools for further creativity and interoperability. Riffing on existing films, photos and songs unlocks creativity. Drawing from the public domain preserves human accomplishment and refreshes it. These are easy to see, but worship?
Copyright and liturgy -- literally, "work for the common good" -- exist (for some sensitive souls) in tension. The bonds on what comes from God, or what is given to God, ought to be loose, if made at all. Since this attitude predates personal printing -- think spirit duplicators in the pre-computer ago -- little wonder the limits of liberal licensing extend to redistribution or free (that is, sponsored) distribution (one example) and not adaptation. In the United States, the public domain ascription of the Episcopal Church's prayerbook is the exception that proves the rule: it has been widely adapted and modified. Unitarian Universalists could take this attitude to heart.
Gladly, I can point to one example that should still be effect and, for some, still useful. From the introduction to the 1937 Services of Religion prepended to Hymns of the Spirit (the red hymnal).
All of the services are intended to encourage a larger participation by the people than is sometimes to be found in what is called “Congregational worship,” but which too often is carried on only by the minister and choir with the people as silent auditors. To ensure full participation by the people the printed services should be in their hands, and they should be instructed to respond audibly in those parts assigned to them, which are printed in bold face type. In churches which lack the printed services or wish to follow a simpler form, it is suggested that the order of service, in a sense of the main sequence of events be printed on cards to be placed in the pews or hinged into the hymn books, the minister drawing upon such of the materials included in this book as he finds suitable for the occasion. Ministers wishing to reprint single services on leaflets for use in their own churches are liberty to do so but the words “Copyright by the Beacon Press” must appear in every such reprint and reprints may not be sold.