Geography Markup Language (GML) is an XML application that provides a standard way to represent geographic information. GML is developed and maintained by the Open Geospatial Consortium (OGC), which is an international consortium consisting of more than 250 members from industry, government, and university departments. Many of the conceptual models described in the ISO 19100 series of geomatics standards have been implemented in GML, and it is itself en route to becoming an ISO Standard (TC/211 CD 19136). An overview of GML together with its implications for the geospatial web is given in this paper.