Handsfree.js is described as 'Build handsfree User Experiences and add face, hand, and pose tracking to your projects in a snap'. There are six alternatives to Handsfree.js for Windows, Linux and Mac. The best alternative is GiMeSpace Cam Control, which is free. Other great apps like Handsfree.js are FaceTrackNoIR (Free, Open Source), FreeTrack (Free, Open Source), TrackIR (Freemium) and VSeeFace (Free Personal).
Head tracking software for webcams, Nintendo Wii Remotes and NaturalPoint cameras (TrackIR, SmartNav and OptiTrack). Tracks a variety of customizable model configurations with up to six degrees of freedom.
Head tracking software for TrackIR and SmartNav cameras that provides game profiles, calibration curves, hotkey controls and a 3D display for testing. Works with TrackIR Enhanced games as well as specified mouse, keyboard and joystick emulation software.