In Martin’s post and the comments there are some links to great resources to get going with accessibility:

Apple’s Accessibility Developer Page.

Assistive Technology for the Mac Resources

Assistive Ware Videos

At WWDC ’06 I went to the Accessibility session and it was the best Hands-On sesssion I’ve been to at WWDC. The 2006 Session video does not seem to be available any more, but the 2008 session can be found from the link below. It requires access to ADC on iTunes, you may need to log into ADC on iTunes first, or simply look for session 326.

WWDC ’08 – Session 326 – Application Accessibility

The 2006 session had an excellent sample application, Dicey, that takes you through stages of increased accessibility. It can be found here:

Dicey Sample Code

However I would like to extend Martin’s challenge. Most independent Mac software developers sell their products exclusively via the web. Therefore for their software to be fully accessible, Mac developers need to make their websites accessible as well.

Information on this can be found at W3C, the web’s standards body, and elsewhere:

W3C’s Accesibility Initiative

Dive Into Accessibility Guide

I would call on all Mac developers to take up the Mac Accessibility Challenge.