For a long time, if you said “head tracking” in a flight sim forum, what people actually heard was TrackIR . Not “a head tracker”. Not “IR tracking”. Just TrackIR. That did not happen because it was the only option. It happened because TrackIR arrived early, worked well enough, and convinced game developers to treat its interface as the  standard. If a sim proudly said “TrackIR supported,” players knew exactly what that meant, and many went out and bought the hardware just fo