x-post from http://theeyetribe.com/forum/viewtopic.php?f=22&t=503&sid=805109a608a60b7b8bb7404f91c33f53
OptiKey is an assistive on-screen keyboard which runs on Windows. It is designed to be used with a low cost eye-tracking device (including TheEyeTribe) to bring keyboard control, mouse control and speech to people with motor and speech limitations, such as people living with ALS / MND. It works out of the box once you have your eye-tracking device installed and allows selections to be made using dwell selection, as well as physical buttons and assistive devices. If you do not have an eye tracking device you can use OptiKey with a mouse.
OptiKey was written to challenge the outrageously expensive, unreliable and difficult to use AAC (alternative and augmentative communication) products on the market. It is, therefore, fully open-source and free. Forever.
Download it, read about, check out the source code (C#) and watch the demo video at http://www.OptiKey.org
(Are you, or do you know, someone who could benefit from OptiKey? Please email me - I'd love to help and know that my software has been helpful to someone.)