KMLstandardi

KMLstandardi, commonly known as the KML standard, is an XML-based language for expressing geographic annotation and visualization on maps and Earth browsers. It enables users to describe points, lines, polygons, overlays, and 3D models, along with styling, time information, and data attributes. The format originated with Keyhole, Inc., and gained broad adoption after Google acquired Keyhole. The Open Geospatial Consortium (OGC) has published and maintains the official KML standard as an interoperable specification, supporting cross‑vendor compatibility among mapping tools and services.

A KML document begins with the kml root element and typically contains a Document or Folder element that groups features. Core geography types include Point, LineString, LinearRing, and Polygon, plus MultiGeometry for combining shapes. A Placemark associates a geometry with metadata such as name and description, and may include ExtendedData for schemas and data fields. Coordinates are expressed as lists of longitude, latitude, and optional altitude values in degrees and meters. The standard also defines styling through Style, IconStyle, LabelStyle, and PolyStyle, with StyleMap enabling different appearances. Time primitives (TimeStamp, TimeSpan) and Region elements support temporal and geographic constraints. The gx extensions add features such as 3D tracks (gx:Track) and enhanced time geometry. Overlays such as GroundOverlay, ScreenOverlay, and Model enable non-geometric content and 3D representations.

KML files (.kml) and compressed KMZ archives are used for data exchange. The format is widely supported by Google Earth and many GIS tools, though some legacy viewers implement only a subset of features. See also: KML, OGC KML Standard, Google Earth.