Expert Markup Handlers for AT:
A Proposal From Open A11y

Open A11y Proposal: A Standard to Enable AT Interaction with Specialized Content

This Open A11y panel will discuss, and gather additional requirements for its proposed interface specification to facilitate plugins to AT for enhancing knowledge domain accessibility.

Session Level:


60 Minute session

Chair: Dr. Neil Soiffer, Design Science, Inc.
  • Pete Brunet, IBM
  • Dr. Vladimir Bulatov, View Plus Technologies
  • Shawn Djernes, Nebraska Commission for the Blind
  • Gregory J. Rosmaita, Open Accessibility
  • Janina Sajka, Open Accessibility


Generalized content markup (such as HTML) is complimented by markup specifications that facilitate more semantically precise content markup. Examples of specialized, semantically precise markup include MathML and MusicXML. Assistive technology (AT) typically handles generalized content markup, but does not know about specialized markup. Because of this, users of AT are unable to access or navigate specialized markup effectively.

The Open A11y Expert Handlers group is exploring a standardized plug-in mechanism for assistive technology software. The goal of this plug-in standard is to allow AT to use expert software plug-ins to provide access to specialized markup exposed through accessibility APIs, such as MSAA and IAccessible2 on Windows and AT-SPI on Unix/Linux. This plug-in standard will allow AT to rely on expert handler software to enable navigation and provide enhanced, semantically rich access to specialized markup, enabling an AT to more properly render -- visually, aurally, and/or tactilely -- the semantic meaning encoded in specialized markup, wherever such specialized markup is encountered: in the context of a word processor document, a DAISY book, or a web page or application.

The Open A11y Expert Handlers SIG has gathered use cases and developed requirements for proposed plugin specifications covering:

In this session, the panel will explain its work to date and invite comments on its work from the audience. A comparison with existing specialized markup assistive technology will be presented briefly as well in order to illustrate the need for the platform and toolkit neutral plugin mechanism Open A11y envisions.

Valid XHTML 1.0 Strict (check it for yourself!)      Web-Content Accessibility Guidelines, Level Triple-A Compliant      Hand-Constructed Using W3C Validated Cascading Style Sheets!

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