gpsd is a service daemon that monitors one or more GPSes
attached to a host computer through serial or USB ports,
making all data on the location/course/velocity of the
sensors available to be queried on TCP port 2947 of the
host computer. With gpsd, multiple GPS client applications
(such as navigational and wardriving software) can share
access to GPSes without contention or loss of data. Also,
gpsd responds to queries with a format that is substantially
easier to parse than the NMEA 0183 emitted by most GPSes.

WWW: http://catb.org/gpsd/