Association of American Geographers (AAG): http://www.aag.org/

Association of American Geographers , Spatial Analysis SIG: http://www.fsu.edu/~geog/sam/

Association of American Geographers (AAG), Geographic Information Systems and Science SIG: http://www.cas.sc.edu/gis/aaggis

Association for Geographic Information (AGI): http://www.agi.org.uk/

Birkbeck College, University of London: http://www.bbk.ac.uk/gisconline/

Centre for Advanced Spatial Analysis (CASA): http://www.casa.ucl.ac.uk

Centre for Spatially Integrated Social Science (CSISS): http://www.csiss.org/

Centre for Computational Geography: http://www.ccg.leeds.ac.uk/

Centre for Computational Geostatistics http://www.uofaweb.ualberta.ca/ccg/

European Commission Joint Research Centre (CEC/JRC) – a web forum for Geostatistics and Spatial Statistics supported by the European Commission: http://www.ai-geostats.org

EURO Working Group on Locational Analysis: http://www.vub.ac.be/EWGLA/homepage.htm

Free GIS Organisation – portal and mailing list: http://www.freegis.org/

Geoscience Australia: http://www.ga.gov.au/

Geospatial Information and Technology Association (GITA): http://www.gita.org/

GIS.COM – geospatial portal sponsored by ESRI: http://www.gis.com

INFORMS OR/MS: http://www2.informs.org/Resources/Computer_Programs/

International Association of Crime Analysts (software list): http://www.iaca.net/Software.asp

International Association for Mathematical Geology (IAMG): http://www.iamg.org/

Market Research Society, Geodemographics Knowledgebase: http://geodemographics.org.uk

NCGIA Core curriculum: http://www.geog.ubc.ca/courses/klink/gis.notes/ncgia/toc.html

Open Geospatial Consortium (OGC): http://www.opengeospatial.org

Open Source Technology Group (OSTG),

Sourceforge: http://sourceforge.net

LP-solve website managed at Sourceforge: http://lpsolve.sourceforge.net/5.5/

Optimisation compendium and best known solutions:http://www.nada.kth.se/~viggo/problemlist/

Optimization Online: www.optimization-online.org

Royal Geographical Society/Institute of British Geographers: GIS in Teaching: http://www.rgs.org/OurWork/Schools/Teachers/CurriculumDevelopments/GIS/

Spatial analysis laboratory, (SAL), University of Illinois: http://www.sal.uiuc.edu/

Spatial Analysis Laboratory, University of Thessaly, Greece: http://www.prd.uth.gr/res_labs/spatial_analysis/

SPLINT: Spatial Literacy in Teaching: http://www.spatial-literacy.org

UK Census Dissemination Unit (CDU): http://census.ac.uk/cdu/

UK Census Output area construction: http://www.geog.soton.ac.uk/research/oa2001/

GB Ordnance Survey: http://www.ordnancesurvey.co.uk/

UNIGIS: http://www.unigis.net/

University Consortium for Geographic Information Science (UCGIS): http://www.ucgis.org

US National Institute of Justice (crime analysis software): http://www.ojp.usdoj.gov/nij/maps/software.html

USGS: http://www.usgs.gov/

USGS Spatial Data Transfer Standard: http://mcmcweb.er.usgs.gov/sdts/

USGS Spectral Lab: http://speclab.cr.usgs.gov

US National Research Council of the National Academies: http://www.nationalacademies.org/

US National Research Council of the National Academies: Geographical Sciences Committee: http://dels.nas.edu/besr/gsc.shtml

US National Research Council of the National Academies: Mapping Science Committee: http://dels.nas.edu/besr/msc.shtml

The Wildlife Society, GIS working Group: http://www.wildlife.org/wg/gis/