KML (formerly Keyhole Markup Language) is an XML language for online mapping, for making geospatial observations, and for controlling your geographic browser experience. KML is supported by Google Earth, Google Maps, MS Virtual Earth, and a number of GIS and spatial software products.
KML is intended primarily as a language for presentation and browser navigation (e.g. “look here”), and provides a rich set of capabilities for that purpose. KML is not intended to describe geographic objects in the sense of GML, and does not provide facilities to create a named kind of geographic entity (e.g. a Road or Building). It can transport a certain amount of data that can be related to a visualization through the use of the <ExtendedData> element added in KML V2.2. KML can transport GML inside an ExtendedData element, however, this GML data is NOT processed (nor is any other ExtendedData content not in the KML namespace) in anyway by the Google Earth browser.
