Virtual GPS is a GPS (Global Positioning System) simulator software. You can use it to emulate a GPS receiver unit connected to your computer. It's ideal when you need GPS input, but you have no signal or you can use it to test your GPS applications. It supports various NMEA 0183 sentences, so it can be used with any GPS mapping software. NMEA 0183 (or NMEA for short) is a combined electrical and data specification for communication between marine electronic devices such as echo sounder, sonars, Anemometer (winds speed and direction), gyrocompass, autopilot, GPS receivers and many other types of instruments. It has been defined by, and is controlled by, the US-based National Marine Electronics Association.
Supported NMEA sentences: GPGLL, GPGGA, GPVTG, GPRMC, GPGSA, GPGSV, GPZDA, GPWPL, GPRTE, GPAAM.

It operates in two modes: simulator mode and file mode. In simulator mode the latitude and longitude coordinates are periodically incremented with a defined step. In file mode the GPS data is loaded from a text file which contains NMEA 0183 sentences.
The GPS data is transmitted periodically to a serial port (UDP ports are also supported). To get the output of the simulator, you can use a null-modem cable which interconnects two physical serial or USB ports, or you can interconnect two bluetooth or Irda ports, or you can use one of the virtual serial port program from the market, which emulates two interconnected serial ports like: Free Virtual Serial Ports Emulator by ETERLOGIC, Virtual Null Modem, Virtual Serial Port Driver, Virtual Serial Port Kit, Advanced Virtual Com Port and others. Another possible software of the program is to broadcast the output of the simulator through serial, USB, bluetooth or IrDA connections.

The license of this software is Free Trial Software, the price is $39.99, you can free download and get a free trial.