Tools to assist users who have visual, mobile or other impairments that make computer use extra-difficult have long been present in Ubuntu, of course. Indeed, as Bacon pointed out, ensuring that everyone can "use all software regardless of disability" is a key component of the Ubuntu philosophy.
To this end Ubuntu has traditionally included the Orca magnifier and screen reader in the default software stack. Additional open source accessibility tools, such as the Hawking toolbar, are also available.
At the same time, the advent of compositing window managers several years back made it easier to build accessibility features into the desktop experience. A number of compiz plugins for improving visual contrast, focus and other aspects of the interface can be enabled in the CompizConfig Settings Manager.
Accessibility in Ubuntu 12.04While there's already an undercurrent of commitment to assistive technologies in Ubuntu, enhancing and perfecting them has become a focus of Ubuntu developers and community supporters ahead of the upcoming release of version 12.04 of the operating system in the spring, Bacon said.
Unsurprisingly, since 12.04 is a longterm-support (LTS) release, the main point of concern for the time being is on finishing and polishing features already in existence, rather than adding new ones. The development team is accordingly looking for volunteers to test accessibility tools to make sure they're ready for deployment.
Because the switch to the Unity interface displaced some of the traditional accessibility features present in the Ubuntu desktop when it was based on GNOME 2, however, a little additional development also will be needed to bring Ubuntu 12.04 up to speed on the accessibility front. According to the development blueprint on Launchpad, "Unity 3D is approximately 80 percent accessible, so far as official oneiric packages go, and unity-2d is 99 percent accessible," but it will take a bit more work to smooth over small but important accessibility gaps before the 12.04 release.
Room for Improvement: Speech RecognitionThis task is vital not only because of its primary importance in improving the lives of Ubuntu users with accessibility difficulties, but also to help Linux keep pace with proprietary competitors. Windows has a rich selection of accessibility tools built in, and plenty of other commercial add-ons are available, but Ubuntu doesn't always match up equally well.
One accessibility area in particular where Ubuntu, and the Linux world generally, has a lot of room for improvement is speech recognition software -- which is important for accessibility reasons as well as for a variety of other purposes. A number of open source tools in this genre exist, but as the Ubuntu wiki notes, none really has the polish or completeness of commercial alternatives. Solving this shortcoming would require huge investment which the Linux community might not be able to support easily, but it would be great to see Ubuntu developers adding some consideration to this topic, perhaps after polishing the existing accessibility technologies in the 12.04 release.