Macintosh

Mac OS X includes "Universal Access".  The program has options geared toward the visually impaired.  The vision options allow the user to magnify the screen, and invert the color combinations for a white on black appearance.  Speech output can also be turned on to read alerts, selected text and text underneath the mouse.  A 90 minute podcast on Mac Accessibility is also available.

The Speech output program in the Mac is called VoiceOver. 

The VoiceOver manual is available as a tagged PDF file.  There is also an audio version of the VoiceOver Manual on the Voiceover downloads page on the Apple website.

There is a VoiceOver key command chart available, this is designed for sighted and partially sighted users.  It is not accessible with speech output.

AssistiveWare has a product called VisioVoice.  This product "enhances" access to the Mac, as it adds multilingual support to VoiceOver.