GPSd is a TCP daemon that displays location data that’s been polled from a connected GPS device. The are a lot of unix location-aware applications that use GPSd instead of communicating directly with a GPS device since it allows more than one application to access the device at a time.
Seth Just sent us a howto on getting GPSd working under OS X, along with a few useful applications.
Luckily, there’s a wonderful open source project called gpsd which provides support for a wide raft of devices and protocols, and talks to an even wider assortment of software. Primarily, I wanted to be able to get my gps to talk to the network scanner Kismac, and Randall Munroe’s cyborg.py script. Both of these were built to take information from gpsd, so I was in business. However, gpsd, which is designed to play nicely with Linux, takes some coaxing under OS X. This is meant to describe how I got it all running.
The documentation also walks you through getting GPSd working with the free gpsdrive navigation software. If you have a Mac laptop and a GPS, it’s worth your half hour of time to get all of this running. You never know when you’ll need to find a public access point or get last minute directions.