The Crystallographic Society of Japan (CrSJ) - Details about the society, including news and annual meetings. International Union of Crystallography (IUCr) - Serves the world community of crystallographers. Society of Crystallographers in Australia and New Zealand (SCANZ) - Includes lists of officials, conference information, membership information, newsletters, and links to educational resources. Czech and Slovak Crystallographic Association (CSCA) - Association bulletin, information on seminars and conferences, and crystallography resources. Swiss Society for Crystallography - Membership and meetings information. Site in English, French and German. European Crystallographic Association (ECA) - Includes minutes and reports of its executive council and groups, conference information, related news and lists of officials and rules, as well as membership information. The Pittsburgh Diffraction Society - News and information on conferences. American Association for Crystal Growth (AACG) - Includes information on conferences, membership information, and a list of positions vacant in this field. British Crystallographic Association (BCA) - Information about the activities of its groups, conference information, index and introduction to its newsletter, and related links. IUCr Commission on Mathematical and Theoretical Crystallography - Research themes, members and information about meetings. Special Interest Group on Aperiodic Crystals - The main classes of aperiodic crystals are incommensurate modulated systems, incommensurate magnetic systems, incommensurate composites, polytypes and quasicrystals. Includes news, conferences, publications and software. IUCr Commission on Crystallography in Art and Cultural Heritage - Research themes, activities, meetings, members, bibliography.