The World Council of Churches is a global fellowship of more than 350 churches in 120 countries. It is the broadest and most inclusive among the many organized expressions of the modern ecumenical movement, whose goal is Christian unity.
Its library, housed at the Ecumenical Institute in Bossey, Switzerland, holds about 100,000 volumes constituting a unique collection on ecumenism and the history of the ecumenical movement. Its archives, housed at the Ecumenical Centre in Geneva, preserves the records of the World Council of Churches as well as of various other ecumenical organizations or movements and of personal papers of ecumenical personalities. The collection contains paper documents and photographs, representing some 2,000 running meters.