I know a skilled programmer/cryptologist who can no longer use a
keyboard. He has an EyeGaze system (http://www.eyegaze.com/)
but apparently the software that comes with it kind of stinks so 
he's getting very frustrated. The method of using EyeGaze to control a 
Windows PC via a serial port is supposedly based on a documented
standard, so I think setting it up to control a Linux PC should be doable.

I'm a complete novice in the topic of accessibility, so any
advice that applies to handling low mobility with Free Software 
would be much appreciated.

Some specific questions I've turned up so far:

* Anyone have experience with dasher? 
  Can you configure dasher to handle the whole desktop, including menus?
  If so, does that require everything be a gnome app to work properly?

* Does Linux have any support for the standard called GIDEI, short for
  General Input Device Emulating Interface? (This is what EyeGaze uses 
  for Windows control)
  http://www.eyegaze.com/content/skeys-program
  http://trace.wisc.edu/docs/gidei/gidei.htm