it actually uses Microsoft's VirtualEarth, which is basically a GoogleEarth ripoff that you cant freeroam like GE and are only limited to certain areas (unless they updated it)
I use GE when i go on trips. Me and a buddy just went on a 3 hour drive through windy roads, i printed out in-depth aerials and i was the navigator like on a rally, "hard left coming", "gradual right followed by a 90* left". his little srt4 was just ripping up the turns, that car sticks like no other now.