Members of Congress continue to demonstrate an ongoing interest in the efficiency and effectiveness of United Nations (U.N.) development activities, both in the context of U.N. reform and broader U.S. development and foreign assistance efforts. Thirty-two U.N. agencies, funds, programs, and offices play a role in development. These entities, collectively referred to as the U.N. development system (UNDS), are independent intergovernmental organisations with distinct mandates, rules, membership, and financial resources. They work to help countries achieve social and economic progress through a range of development activities, including program implementation, technical assistance, providing forums for intergovernmental co-operation, setting and facilitating international standards and norms, advocacy and awareness raising, and research and data collection. This book discusses the origins and evolving role of the UNDS and its perceived strengths and weaknesses, with a focus on the current UNDS structure, funding levels and trends.