I have been using GPSGate for years. It is very stable/reliable, and I believe they just made the one-input to two-outputs (GPSGate Client Express) version free.
Download link here. GpsGate Downloads - GpsGate.com
The 'standard' version, which comes with the free download and is free for 14 days, will do multiple inputs to multiple outputs. I regularly run on an older slower laptop
, two inputs (GPS and AIS) to about 4 programs. It has a lot of other features, including the ability to send GPS data over the internet
(if you've got an internet
connection, of course).
This program will also turn a Garmin
GPS 12-which is relatively useless unless you invest in now-obsolete Garmin software
, into a useful NMEA
GPS which you can use for navigation
But it looks like it only runs on Windows.