file extension KML

File extension KML description:

Keyhole Markup Language file. The file format used by Google-Earth, to allow developers to define custom layers which can be displayed by Google-Earth. The file contains Keyhole Markup Language (kml), which is defines geographic modelling features such as points, lines, images and polygons.

KML, or Keyhole Markup Language, is an XML grammar and file format for modeling and storing geographic features such as points, lines, images, and polygons for display in Google Earth. This document describes KML version 2.0 for Google Earth version 3.0 and later. (Earlier versions of KML can be read into Google Earth and saved out as KML version 2.0.)

You can use KML 2.0 to:

• Specify icons and labels to identify locations on the planet surface
• Create different camera positions to define unique views
• Use image overlays which are attached to the ground or screen
• Define styles to specify feature appearance
• Write HTML descriptions of features—including hyperlinks and embedded images
• Use folders for hierarchical grouping of features
• Dynamically fetch and update KML files from remote or local network locations
• Deliver current view details from the client to the server in order to fetch KML data based on changes in the 3D viewer

A KML file is processed by Google Earth in a similar way that HTML and XML files are processed by web browsers. Like HTML, KML has a tag-based structure with names and attributes used for specific display purposes. Thus, Google Earth acts as a browser of KML files.

The following list summarizes the latest features in KML version 2.0:

• A new object, , controls the behavior of network files fetched through network links.
• The default format for files written by Google Earth is KMZ. This is a compressed KML file that can be opened by any software that understands common ZIP file formats. The benefit of this is that images are self-contained in the file and do not need to be hosted on a network server, as with KML 1.0.
• The tag now supports a vast array of standard HTML features, such as anchors, images, rich text, and tables.
• The old tag has been replaced with a new tag.
• The syntax of the feature has been updated.
• Styles are now much more powerful. They consist of styles for each geometry currently supported by the client: , , , and .
• Lines can now be optionally tessellated over terrain.
• The tag has been deprecated in favor of using .
• Network links are now able to return the current view to the server, allowing the server to return location-specific KML files.

Additional material exists that can help you use and optimize your implementation(s) of KML. These include:

• KML tutorial – This document provides a hands-on lesson that demonstrates how KML works. View this tutorial here: http://www.keyhole.com/kml/kml_tut.html
• Google Earth KML message board – Visit this forum to learn about and share KML-related information with other users of KML. You can visit this message board here: http://bbs.keyhole.com/ubb/postlist.php/Cat/0/Board/SupportKML