Adapted keyboard (Overlays)

There are a vast variety of alternatives to the standard keyboard. My post Keyboard Alternatives lists a few. For this post I wanted to expand on overlays and specific keyboards that can be used. A popular brand of customizable keyboards with interchangeable overlays is IntelliKeys. This brand provides a variety of pre-printed overlays and also can be used in conjunction with the software Overlay Maker 3 to create custom overlays.