In the last few years, IRIS (Incorporated Research Institutions for Seismology) has been transformed from a special initiative to a national program for seismological study of the interior of the Earth. Current efforts include the deployment of a global seismographic network (GSN), which will consist of 100 broadband, high dynamic range stations; a program for array studies (PASSCAL) consisting of 1000 digital recording systems and seismometers; and a data management system to support the research community's access to data. In addition, IRIS is pursuing new initiatives such as the US/USSR Joint Seismic Program and the Trans-Pacific Cable. The third annual IRIS Workshop was held on Hilton Head Island, South Carolina, March 11–13, 1991. The workshop was organized by Paul Silver of Carnegie Institution of Washington, D.C., and Douglas Wiens of Washington University, St. Louis. More than 100 scientists participated in the meeting.