[NOTE: this is an experimental schema in alpha form.] This schema defines extensions to be used with the GPX 1.1 schema in support of the walkingtools project. The extensions are to the GPX wpt (and by extension) rtept types. The root element defined by this schema is intended to be used as a child element of the "extensions" elements in the wpt (and rtept) element in the GPX 1.1 schema. The GPX 1.1 schema is available at http://www.topografix.com/GPX/1/1/gpx.xsd. All durations in walkingtools.gpx are in miliseconds. Change Log Version 0.0.3 - Made radius a required element. Version 0.0.4 - fixed xmlns and targetNameSpace Version 0.0.5 - updated to reflect new Walkingtool Reference APIversioning... no significant changes to the schema. wptExtension is the root element in the wtgpx extension. Media and other extensions to GPX wpt You must include the version number. Audio associated with the wpt ISO 639-3 descriptor of the spoken language: http://www.sil.org/iso639-3/ Image associated with the wpt Video associated with the wpt ISO 639-3 descriptor of the spoken language: http://www.sil.org/iso639-3/ Allows the definition of an arbitrary alternative event associated with the wpt