Keyhole Markup Language (KML) is an XML notation for expressing geographic data and visualization within Internet-based, two-dimensional and three-dimensional map browsers. The format was acquired by Google in 2004 and became the standard used in the Google Earth application. In 2008, the format became an international standard of the Open Geospatial Consortium.
The KML format has a structure similar to XML, but specifies a set of features, such as place marks, images, polygons, 3D models and textual descriptions. Each location always has a longitude and a latitude. The files are distributed in KMZ packages, which are zipped KML files with a .kmz extension. The contents of a compressed package include a single KML document ("doc.kml") and optional subdirectories containing images and other files referenced in the KML. A typical KML document is presented as follows:
<?xml version="1.0" encoding="UTF-8"?>
<description>Cidade de São Paulo</description>