SpecialNeeds
Special Needs in Educational Software
Elsewhere in this Wiki, the AccessibilityTeam page addresses accomodating populations who have difficulty using certain software features.
However, generally speaking, those accomodations simply address improving the usability of standard software, often by offering alternative ways of using it. That does not address the needs for different educational tools.
Deafness
For example, students who are pre-lingually deaf (those who are born deaf or lose their hearing before acquiring language) have a much harder time learning to read and write. This leads to a host of other problems later in their education.
According to the [http://gri.gallaudet.edu/Demographics/ Annual Survey of Deaf and Hard of Hearing Children and Youth], during the 2003-2004 school year, there were approximately 39,000 deaf children attending elementary or secondary schools in the United States. And those are only the documented children. (I haven't dug up worldwide figures.) Some of those students do have language skills already, but a good percentage do not.
At Gallaudet University, in Washington, DC, there is a primary school, a secondary school and a university all serving deaf or hard-of-hearing individuals. All told, there are about 1700 deaf/HoH students attending one of the three schools.