Many applications may wish to use location data simultaneously on one computer. Also, there are several incompatible protocols for delivering location information, including flavors of NMEA-0183, Rockwell and SiRF binary protocols, AIS, and others. To solve both of these problems, Unix developers created the gpsd daemon, which interprets all of the protocols and delivers a common data format to multiple location consumers.
YAAC supports connecting to a gpsd daemon (if one is present on the system) and receiving location data in the gpsd JSON format. To do so, you merely need to tell YAAC at which network port the daemon is running. By default, this is assumed to be on the local computer running YAAC at the gpsd standard TCP port number, but this can be changed (for example, to share a single GPS among a local-area network of users at a field command post). These settings can be configured on the port editing dialog: