Rather than confine itself to one long string of keys, this novel keyboard interface uses hexagonal keys in a honeycomb pattern to arrange notes ordered according to a harmonic table. Called the Axis, this innovative MIDI controller is in commercial production.
This is not a alternative tuning system, but an alternative keyboard. All twelve notes of the traditional Western scale fit into onto a 2-dimensional surface with a visible logical pattern.
Their web site says:
Starting from any note, the next note up-to-the-left is a minor third above the starting note. The next note directly above is a fifth above the starting note, and the next note up-to-the-right is a major third above the starting note.
Semitones are in horizontal lines, like the semitone between Minor and Major 3rd.
In this arrangement, a minor triad (three note chord) has the shape of a left-facing triangle, and a major triad has the shape of a right-facing triangle.
The Harmonic Table pattern can be extended in all directions, and all intervals, chords and scales have the same shape in any key. See some chord shapes.
The best explanation is simply to see it at work. Here is rock musician Jordan Rudess playing it after a few months practice:
Will anyone use it? If you play more than one instrument you already use more than one fingering system. Some folks will think of this as a new instrument. New instruments have a tough uphill challenge in becoming accepted, but often win a small following of dedicated fans. The long-tail of instruments. For some types of music, this keyboard may be perfect. (Thanks John La Grou)