» APS Topical Group on Gravity    Topical interest group of the American Physical Society. Includes a brief description of the group, information about prizes, and its newsletters "Matters of gravity".    http://www.apsgravity.org/

» Apples with Apples    Association of numerical relativity groups, with the aim of developing standards for comparing the groups' different simulation codes and the results obtained therewith.    http://www.appleswithapples.org/index.html

» Australasian Society for General Relativity and Gravitation    Includes a newsletter, information on events, and links to related research groups.    http://www.physics.adelaide.edu.au/ASGRG/

» Gravitational Physics Section of EAS and EPS    Section of the Joint Astrophysics Division of the European Astronomical Society and the European Physical Society    http://www.astro.auth.gr/gps/

» Gravity Research Foundation    Foundation best known for its prestigious annual essay competition.    http://www.gravityresearchfoundation.org/

» International Society on General Relativity and Gravitation    Includes information about the society's officers, journal and conferences.    http://www.maths.qmw.ac.uk/grgsoc/

» LISA International Science Community    Website for the community of scientists involved in doing research for and with the proposed space-borne gravitational wave detector LISA.    http://www.lisa-science.org/

» Spanish Society of Gravitation and Relativity    Includes information about membership, officers, conferences and about Spanish relativity groups.    http://www.segre.es/iindex.htm

» The International Light Cone Advisory Committee (ILCAC)    Dedicated to efforts to solve quantum field theories by use of a special, relativity-based method known as light-cone quantization. Includes list of members and information about the committee's workshops and meetings.    http://www.slac.stanford.edu/xorg/ilcac/