Keyhole Markup Language (KML) is an XML (eXtensible Markup Language)-based language schema for expressing geographic data and visualization on existing or future web-based, 2-D maps and 3-D Earth browsers including Google Earth (Google Inc. 2008), Google Maps, Google Maps for mobile, NASA WorldWind, ESRI ArcGIS Explorer, and Yahoo! Pipes.
KML files can be created using Google Earth, Google Maps, or ESRI ArcGIS, or using a plain text editor to create the files from scratch. KMZ files are zipped KML files packaged with images. Information about KML/KMZ can be found in: