The TomTom is a portable car navigational device that allows a user to get text and voice instructions to a particular place. There are a number of different models of TomToms, including the TomTom One 3 GPS Navigator, the TomTom GO 920, the TomTom GO 720 and the TomTom GO 510.

There are a number of hacks available for the TomTom—many software modifications can be made to allow the TomTom 3 to perform extra functions not included in the original device.

The TomTom series of devices run on a version of the Linux operating system known as TomTom Linux, or TTL for short. The devices use the ARM processor to run on. Based on this information, hackers began by developing programs that would run on Linux using the same processor. However, the real breakthrough came when TomTom released the source code for it's Linux distribution at the request of the GPL Violations project. Since the original source code for Linux is controlled by the GNU General Public License, it was a violation for the makers of TomTom to compile the code without publishing the changes they made. While the mapping and navigation applications of the TomTom remain proprietary, the access to the base operating code allowed hackers to experiment further with other applications for the device. Customized applications that have been developed after this breakthrough have included an MP3 player, WiFi sniffer, a radar detector and a crypto-key server responding to Bluetooth requests.iTWire: hacking the TomTom