• CityGML homepage at the Open Geospatial Consortium (www.opengeospatial.org/standards/citygml)
• OGC CityGML Standards Working Group (www.opengeospatial.org/projects/groups/citygmlswg)
• Homepage of the Special Interest Group 3D of GDI DE (www.sig3d.org). The old web page with many meeting minutes and other material can still be found at www.ikg.uni-bonn.de/sig3d/ (in German only)
• Homepage of the Geodata Infrastructure North Rhine-Westphalia  (https://www.geoportal.nrw.de/application-informationen/gdi/gdinrw/index.php; most of the contents of the old homepage www.gdi-nrw.de can be found at www.ikg.uni-bonn.de/gdinrwarchiv)
• European Spatial Data Research Organisation EuroSDR (www.eurosdr.net)
• Open Geospatial Consortium  (www.opengeospatial.org)
• OGC 3D Information Modelling Working Group (www.opengeospatial.org/projects/groups/3dimwg)
• ISO/Technical Committee 211  (www.isotc211.org)
• BuildingSmart Alliance (formerly called 'International Alliance for Interoperability' www.buildingsmart.com); German chapter (www.buildingsmart.de)
• Web 3D Consortium (www.web3d.org)
• Organization for the Advancement of Structured Information Standards OASIS (www.oasis-open.org)
• Khronos Group (www.khronos.org)

• Industry Foundation Classes (IFC 2x3, ifcXML) (www.buildingsmart-tech.org/specifications/ifc-releases/ifc2x3-release)
• Industry Foundation Classes for GIS (IFG) (www.iai.no/ifg/)
• X3D (www.web3d.org/x3d/specifications/x3d_specification.html)
• VRML97 (www.web3d.org/x3d/specifications/vrml/)
• GeoVRML (www.geovrml.org)
• X3DOM (www.x3dom.org)
• Universal 3D (U3D) (www.ecma-international.org/publications/standards/Ecma-363.htm)
• Keyhole Markup Language (KML) (www.opengeospatial.org/standards/kml)
• COLLADA (www.khronos.org/collada/)
• Synthetic Environment Data Representation and Interchange (SEDRIS) (www.sedris.org)
• Building Information Spatial Data Model (BISDM) (www.bisdm.org)
• Green Building XML (gbXML) (www.gbxml.org)

• Geography Markup Language 3.1.1 (www.opengeospatial.org/standards/gml)
• OASIS xAL extendible Address Standard (xml.coverpages.org/xnal.html)
• INSPIRE Data Specifications (inspire.jrc.ec.europa.eu/index.cfm/pageid/2)
• Geographic Data Files (GDF) (www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=30763)
• Amtliches Liegenschaftskataster-Informationssystem (ALKIS), the new German cadastre standard based on ISO 191xx standards and GML3 (www.adv-online.de/icc/exteng/broker.jsp?uMen=01a700d3-6ed6-0bfb-8f23-50376a112976)
• Objektkatalog für das Straßen- und Verkehrswesen (OKSTRA), German standard for the representation of traffic and transportation facilities (www.okstra.de)
• Ordnance Survey Mastermap (OS Mastermap), British standard for the digital map of Great Britain (www.ordnancesurvey.co.uk/oswebsite/products/osmastermap/)
• LandXML  (www.landxml.org)
• Landesbauordnungen der Länder Deutschlands (Building codes / regulations of the German states). For example, Landesbauordnung North-Rhine Westphalia (BauO NRW) (sgv.im.nrw.de/lmi/owa/pl_text_anzeigen?v_id=5820031106092333838)

• (this is list is pretty outdated; I'll try to come up with a list of conference series that are related shortly)
• 1st International ISPRS / EuroSDR / DGPF Workshop on Next Generation 3D City Models, 21-22 June 2005 in Bonn (www.ikg.uni-bonn.de/NextGen3dCity)
• 11th International Conference on Urban Planning & Regional Development in the Information Society CORP 2006 on February 13th - 16th 2006 in Vienna, Austria (www.corp.at)
• 25th Urban Data Management Symposium on May 15-17, 2006 in Aalborg, Denmark (www.udms.net)
• International ISPRS Workshop on 3D Geoinformation 2006 (3DGeoInfo '06) on 7-8 August 2006 in Kuala Lumpur, Malaysia (www.gdmc.nl/zlatanova/3Dgeoinfo2006/)
• 3rd International Conference on Virtual City and Territory on October 25-27, 2006 in Bilbao, Spain (www.labein.es/3ctv-bilbao/presCong_en.htm)

Created and maintained by Thomas H. Kolbe
Last update: 2012-05-30