Since it came up, there is also a Dvorak left-handed and right-handed keyboard (and a two-handed keyboard). Google Dvorak keyboard. We used to be able to remap the keyboard layout in Windows and then you just switch the key tops on your keyboard to match the electronic layout. No cost, unless you want to buy an extra keyboard to keep from having to switch the key tops back and forth.
It's a good way to be able to speed up a person's ability to type much faster, even if you're two-handed, the Dvorak layout will at least double your speed. Of course, you do need to practice so you can do the touch type.
The downside is, it's not really practical if you're supporting several systems with the current QWERTY layout.