Maltron Layout
The Maltron Layout is specially designed for the Maltron Keyboard, a design copied by the more well-known Kinesis Contoured Keyboard .
The distinguishing feature of Maltron layout is that the key e is positioned for the thumb. You will need a keyboard with a thumb key to use the Maltron layout.
Also, the Maltron layout is more efficient than Dvorak or any other, simply because it places the mostly frequently used key e on the thumb.