W3C Geolocation API

The Geolocation API defines a high-level interface to location information associated with the hosting device, such as latitude and longitude. The API itself is agnostic of the underlying location information sources. Common sources of location information include Global Positioning System (GPS) and location inferred from network signals such as IP address, RFID, WiFi and Bluetooth MAC addresses, and GSM/CDMA cell IDs.

The API is designed to enable both "one-shot" position requests and repeated position updates, as well as the ability to query the last-known position. Location information is represented by latitude and longitude coordinates and optionally by reverse geocoded address information.

Google Gears and Firefox 3.1 support the specification.