It is an OSK, minus the keyboard
Pros & Cons:
I love how innovative Dasher is - it's an OSK, minus the keyboard. Let me explain. The team at the Inference Group at Cavendish Laboratory, Cambridge, have developed a way for people to enter text by using alternative methods. From the Dasher website:
"[Dasher can be used] when operating a computer one-handed, by joystick, touchscreen, trackball, or mouse; when operating a computer with zero hands (i.e., by head-mouse or by eyetracker); on a palmtop computer; on a wearable computer.
The eyetracking version of Dasher allows an experienced user to write text as fast as normal handwriting - 29 words per minute; using a mouse, experienced users can write at 39 words per minute."
It takes a little getting used to, but I found that I improved quite quickly with a bit of practice. You 'steer' your mouse toward the next letter you need, and the letters 'fly' towards the cursor from the right of the screen. Don't click, don't drag, just steer or 'drive' to the next letter. And don't be afraid to cut corners or go back (you'll see what I mean when you use it).
All letters are in alphabetical order, top to bottom, lower case to upper case, but Dasher presents the next letter with a size that is proportional to the probability of your needing it. The software continually strives to anticipate and accommodate. You can see this concept at work in the screenshot above (click it for a larger image). Four or five of the most likely continuations of the prefix "pro", pertinent to the sentence being entered, are popping out at you. But if you want instead to compose the word "prolific", you would steer your mouse between "-ject" and "-mise", and the needed letters are guaranteed to arise out of the ever-changing flux. By the way, those little square shapes represent the space character.
Continuing the use of the driving analogy, when the letters are 'run over', they are registered at the top of the screen to build the words, sentences and paragraphs. This may be saved later as text files or cut and pasted into other applications.
Dasher supports many languages, and can also improve its predictive capabilities by learning the words you use often.
Besides the desktop versions, it also has mobile versions for Android and iOS devices.
Dasher was reviewed by Gizmos Freeware on