HTML5 Geolocation API allows users to share their location with web applications by capturing the approximate longitude and latitude coordinates of the user with their permission. The Geolocation feature can be used to enrich many types of web applications by adding automatic location information. For example, users can share their locations with their friends in a social network, can be guided to a direction or location based ads can be displayed. The Geolocation API can be paired up with different maps, such as Google Maps, Yahoo Maps, Bing Maps or Nokia Ovi Maps.
As far the use privacy is concerned, the HTML5 specification explicitly requires the user permission to share its location to any application requesting Geolocation information.Almost all modern browsers Firefox 3.5+, Opera 10.6+, Chrome 5+, Safari 5+ and Internet Explorer 9+ support Geolocation API.