The Institute of Museum and Library Services (IMLS) is committed to bringing together museums and libraries across the country for conversations dedicated to developing a better understanding of the roles of libraries and museums as providers of public service to communities. The Future of Libraries and Museums in the 21st Century Planning Meeting, which took place July 7-8, 2008, in Washington, D.C., was convened by the National Academy of Sciences and supported by IMLS to bring together voices across and outside the library and museum fields to debate, discuss, and question the future of museums and libraries and gain insight into how the conversation could unfold in subsequent discussions in the field at large. This meeting brought together leaders from across the disciplines in the library, museum, research, scientific, technology, and education fields to help define the central issues, challenges, and opportunities that libraries and museums are likely to face in the coming decades. During the course of the meeting, participants considered three areas where significant change is anticipated over the course of the 21st century: (1) The relationship among museums, libraries, and society; (2) The evolution of the role or roles of museums and libraries; and (3) The future support, environment, and infrastructure for museums and libraries. This publication is intended to provide some structure for and spark ongoing conversation and dialogue among museum and library professionals, policy makers, funders, users, researchers, and partners from the private and public spheres regarding their own institutions, networks, and communities. (Contains 3 footnotes.)