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 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.

Applications that presently use gpsd include pyGPS, Kismet, GPSdrive, 
gpeGPS, position, roadmap, roadnav, and gaia.

See README.build for some additional build options that might be useful.