TrackIR - TrackIR adds depth to the PC gaming experience by enabling players to take control of the in-game view.
VRChat - Create and play in virtual worlds with others
FaceTrackNoIR - FaceTrackNoIR is only available for Windows-based PC's (sorry, we have to start somewhere) and...
Spatial - Collaborate from anywhere in AR
GiMeSpace Cam Control - Control your computer by making gestures in front of the webcam.
Gather Town - Spatial video-chat worlds for work and play