Keyhole Markup Language (KML) is an XML notation for expressing geographic annotation and visualization within Internet-based, two-dimensional maps and three-dimensional Earth browsers. KML was developed for use with Google Earth, which was originally named Keyhole Earth Viewer. It was created by Keyhole, Inc, which was acquired by Google in 2004. KML became an international standard of the Open Geospatial Consortium in 2008. Google Earth was the first program able to view and graphically edit KML files. Other projects such as Marble have also started to develop KML support.
I’m sorry to say Mike above is wrong. He’s been deceived by the file name and didn’t actually look to see what it did I guess. Our geo_sitemap.xml file is a normal XML sitemap, linking to the KML file, it’s not actually a geo sitemap, it’s just named that way for historic reasons.
See the first question on this thread and Susan Moskwa’s answer
Steps to Create a KML Sitemap for Google Code Snippet
Download Google Earth. Just google it to get the download information. Follow along at 00:19 or just watch the video below. Same video! =)
If you watch my HOWTO video, below, you’ll see at 2:08 that I created a sitemap feed. Here is that code example. Change the filename from geolocation.xml to whatever you want with the caveat that there be NO spaces in the filename. Un*x systems do not like that.
Setup a Google Webmaster’s Account. Follow along at 02:38 and setup a new feed file for sitemap entries. Or, just wait for 2:38 to go by on the video below. =)