Recs.
Updated
The most popular alternative, and an ANSI standard. The simplified version changed the number order (and some punctuation) from the classic to more closely resemble QWERTY.
SpecsUpdate
Pros
Pro Opportunity to learn proper touch typing
Most people passively learn and use QWERTY-based layouts before switching to Dvorak. The switch gives them an opportunity to completely relearn 10-finger typing, which is where a significant portion of the speedup comes from. Coupled with more ergonomic key placement, this makes for a more enjoyable typing experience.
Pro You can reuse qwerty layout
Since letters and symbols only change place, but not key, you can change the keys on your keyboard and get a full comfortable Dvorak layout, without having to buy a new keyboard.
Cons
Con Inconvenient for common key-shortcuts
Key bindings common to most applications, such as Ctrl+Z/C/V, can't be done on the left hand while mousing with the right. Shortcuts for other applications are out of the QWERTY positions they were designed for and aren't so convenient to access.
Con F is too hard to reach
F
is not an especially common letter, but it's used much more than the rare letters JQZ
. Why is it on one of the most difficult spots on the keyboard? It's also used in OF
, one of the more common bigrams, ranked at #13. Maybe some other languages use Z
more than English, but why is F
harder to reach than Q
?
Con Not the standard keyboard layout
It will be difficult to frequently switch between computers.
Con Not easy on the right pinky finger
Most useful symbols for programming are on the right pinky finger, which is not very comfortable.
Con Not actually faster than QWERTY
Maybe it's more ergonomic, but that's debatable. You'll certainly get more benefit from an ergonomic keyboard than a change in layout. Dvorak's reputation for speed is due to a typo in the initial press report, and a biased (and since discredited) study run by Dvorak himself. Dvorak is all hype and no substance.