doc.kmland a subdirectory called
doc.kmlfile contains the location data using an XML schema called KML. The
filessubdirectory contains image files for the icons for each placemark and possibly for use in the "description" part of the placemark, which can use HTML markup.
doc.kmlfile from a database using the "Home Port" location set by some participants on Pirates@Home. The example at http://pirates.spy-hill.net/user_profile/placemarks.kml can be viewed in Google Earth, but has no image icons (so you get the default push-pin). I will add further features later.