The Apple Developer Connection has published an article on Universal Access, the umbrella name for making computers more usable by those with disabilities. The article offers guidelines and tips for making your application more accessible, and for tapping into Mac OS Xis built-in Universal Acceess tools. From the article:
Apple has been working hard on Universal Access and itis time for you, the developer, to start incorporating Universal Access into your application if you havenit done so already. This article guides you through the reasons you will want to provide Universal Access, the architecture underlying the technology, and how to get started incorporating these features into your app. Weill also give you a preview of whatis to come in Tiger -- and itis quite a lot -- but donit wait, you can incorporate key elements of Universal Access into your app right now.
You can find the article at the Apple Developer Connection.