Happy Birthday to hymnwriter Brian Wren, who is seventy-four years old today. He is certainly one on the best known contemporary writers of hymn texts; several appear in many modern hymnals. He was ordained in 1965 in the United Reformed Church in England but has now lived for many years in the US, currently in Georgia with "his partner in marriage and ministry," the Reverend Susan Heafield, a United Methodist minister. Their joint website, Praise Partners, contains much more information on their lives and works.
I would guess that Wren probably has written a greater number of texts that have never appeared in a denominational hymnal than those that have. It's true that hymnwriters generally write more texts than are ever accepted for publication, but it's also true that many of Brian Wren's texts are considered too radical by many. His commitment to writing in inclusive language has only strengthened over time (he first believed it to be an American fad when encountering the idea nearly forty years ago). He also believes that modern hymns should avoid much of the language of the past about militarism and even the kingship of God.
One of his hymns that some may know is Bring many names (which you can see and hear at the Cyber Hymnal). Written more than twenty years ago, it exemplifies everything that some people like about his texts as well as everything that other people don't. The text was considered for inclusion in the Methodist Hymnal of 1989, but lost the committee's recommendation by only one vote. Presumably the Methodists were not ready for a "strong Mother God" (among other things).
Anyway, the hymn did go on to be published in the Unitarians' Singing the Living Tradition (1993), the United Church of Christ's New Century Hymnal (1995), the Anglican Church of Canada's Common Praise (1998), and perhaps a few others I don't know about. It also appears in some supplemental collections that don't have the same wide usage as an official denominational hymnal, such as the Episcopalians' Voices Found (2003). And the Methodists finally included it in their supplement The Faith We Sing (2000).
Others of his texts seem unlikely to be widely used, such as All-Perceiving Lover or Against the clock (you can see these and several others by searching at the links in the first paragraph above). But it's always useful to remember that some of the most well-known hymns sung today were not immediately loved or widely sung at the time of their creation, or even in the lifetime of their writers.
I encourage you to read these two interviews with Wren, one from the Christian Century and one from Reformed Worship. Though they are not as current as I'd like, they do give a better understanding of the themes and ideas that he brings to modern hymnwriting-- he explains them so much better than I ever have.