Dynamic web sites and rich internet applications have recently got
widespread. An important challenge is guaranteeing their
accessibility to all potential users regardless of physical and
cognitive disabilities as well as hardware and software limitations.
To this aim, WCAG 2.0 guidelines have been released as the
newest W3C recommendation for accessible web content, and
WAI-ARIA are reference specifications for accessible rich
internet applications. However, both design resources contain a
huge amount of information, and, like all standards and
guidelines, do not provide designers with a clear design method.
This paper proposes a design pattern language for accessibility to
help web designers create accessible rich internet applications
compliant with the most recent standards. The language has been
implemented as an accessible rich internet application itself,
allowing designers with disabilities to participate in web design.
The results of a preliminary evaluation are finally discussed.