- Union of Concerned Scientists (UCS)
Nonprofit alliance of scientists and citizens working for a healthy environment and a safe world, UCS researches and promotes clean energy and transportation technologies.
- National Bureau of Economic Research
A nonprofit foundation engaging in academic research on the U.S. economy.
- American Association of Variable Star Observers (AAVSO)
Both amateur and professional.
- American Academy of Arts and Sciences
An honorary society which recognizes achievement in the natural sciences, social sciences, arts, and humanities.
- Clay Mathematics Institute (CMI)
Private nonprofit foundation dedicated to increasing and disseminating mathematical knowledge.
- Arnold Arboretum of Harvard University
America's oldest public arboretum displaying over 15,000 woody plants and offering educational programs for people of all ages.
- Cultural Survival
Helps indigenous peoples and ethnic groups deal as equals in their relations with national and international societies.
- Human Rights Education Associates
Supports efforts aimed at introducing human rights concepts and values into educational curricula and teaching practices.
- Electronic Policy Network
A group of research and advocacy organizations and publications, providing online analysis of economics, politics, social trends, and public policy.
- Lincoln Institute of Land Policy
Nonprofit educational institution based in Cambridge, MA and established to study and teach land policy, including land economics, and land taxation.
- Usenet Addresses Service (MIT)
Search for email addresses found in Usenet, by person's name or by organization.
- Center for Progressive Christianity
Encourages the presentation of the Christian message to those for whom organized religion has proved to be ineffectual, irrelevant, or repressive.
- Pugwash Conferences on Science and World Affairs (3)
- Massachusetts Biotechnology Council (MBC)
Nonprofit organization that provides services and support for the Massachusetts biotechnology industry.
- City of Cambridge, Massachusetts
City of Cambridge, Massachusetts, official site. Includes news, important phone numbers, City Hall hours, online services, and calendar of events.
- Dzogchen Foundation
Heart-essence teaching of the non-sectarian practice lineage of Tibetan Buddhism.
- Medieval Academy of America
Supporting research, publication, and teaching in medieval arts, history, law, philosophy, religion, and science.
- Health Effects Institute
Funds research into the health effects of auto emissions.
- Armenia Tree Project (ATP)
Works to advance Armenia's economic and social development through reforestation, providing food, fuel, environmental benefits, and economic growth.