IAccessible2
Encyclopedia
IAccessible2 is a new accessibility
API for Microsoft Windows
applications. Initially developed by IBM
under the codename Project Missouri, IAccessible2 has been placed under the aegis of the Free Standards Group
, now part of the Linux Foundation
. It has been positioned as an alternative to Microsoft's new UI Automation
API.
While UI Automation is trumpeted as "royalty-free", IAccessible2 claims to be an "open standard".
(MSAA) to create a more flexible accessibility API, IAccessible2 fills in perceived omissions in MSAA to match the Java Accessibility API and Assistive Technology Service Provider Interface
(AT-SPI). By extending the MSAA interface, rather than replacing it, IAccessible2 allows "application developers to leverage their investment in MSAA while also providing an Assistive Technology (AT) access to rich document applications." It is also advantageous for Microsoft's commercial competitors, Sun and IBM, to promote an alternative accessibility interface to the Windows platform standard, which explains both their focus on developing non-MSAA/UIA interfaces and their promotion of cross-platform support despite the lack of any AT that is cross-platform that might use it.
Project Missouri was started when the State of Massachusetts
, in the process of adopting the OpenDocument format for its public records, required that the format be made accessible. Increasing the accessibility of dynamic web applications
, for example by exposing custom controls for use with assistive technology
and by filtering streams of new information by type and importance, became a second major focus for the project.
,
Opera Browser
and NonVisual Desktop Access
. Although IAccessible2 was introduced as a Windows accessibility API, Trolltech
are treating IAccessible2 as a potential alternative to AT-SPI on Linux too, and planning to add preliminary support to Qt
4.3.
Accessibility
Accessibility is a general term used to describe the degree to which a product, device, service, or environment is available to as many people as possible. Accessibility can be viewed as the "ability to access" and benefit from some system or entity...
API for Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
applications. Initially developed by IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
under the codename Project Missouri, IAccessible2 has been placed under the aegis of the Free Standards Group
Free Standards Group
The Free Standards Group was an industry non-profit consortium chartered to primarily specify and drive the adoption of open source standards.All standards developed by the Free Standards Group were released under open terms and test suites, sample implementations and other software were released...
, now part of the Linux Foundation
Linux Foundation
The Linux Foundation is a non-profit technology consortium chartered to foster the growth of Linux.Founded in 2007 by the merger of the Open Source Development Labs and the Free Standards Group , the Linux Foundation sponsors the work of Linux creator Linus Torvalds and is supported by leading...
. It has been positioned as an alternative to Microsoft's new UI Automation
Microsoft UI Automation
Microsoft UI Automation is an Application Programming Interface for User Interface accessibility that is designed to help Assistive Technology products interact with standard and custom UI elements of an application as well as to access, identify, and manipulate an application's UI elements...
API.
While UI Automation is trumpeted as "royalty-free", IAccessible2 claims to be an "open standard".
Goals
Whereas UI Automation marks a radical break from Microsoft Active AccessibilityMicrosoft Active Accessibility
Microsoft Active Accessibility is an Application Programming Interface for user interface accessibility. MSAA was introduced as a platform add-on to Microsoft Windows 95 in 1997...
(MSAA) to create a more flexible accessibility API, IAccessible2 fills in perceived omissions in MSAA to match the Java Accessibility API and Assistive Technology Service Provider Interface
Assistive Technology Service Provider Interface
Assistive Technology Service Provider Interface is a toolkit-neutral way of providing accessibility facilities in applications. It was developed by the GNOME project. AT-SPI toolkits provide a logical representation of the content of the application...
(AT-SPI). By extending the MSAA interface, rather than replacing it, IAccessible2 allows "application developers to leverage their investment in MSAA while also providing an Assistive Technology (AT) access to rich document applications." It is also advantageous for Microsoft's commercial competitors, Sun and IBM, to promote an alternative accessibility interface to the Windows platform standard, which explains both their focus on developing non-MSAA/UIA interfaces and their promotion of cross-platform support despite the lack of any AT that is cross-platform that might use it.
Project Missouri was started when the State of Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
, in the process of adopting the OpenDocument format for its public records, required that the format be made accessible. Increasing the accessibility of dynamic web applications
Web accessibility
Web accessibility refers to the inclusive practice of making websites usable by people of all abilities and disabilities. When sites are correctly designed, developed and edited, all users can have equal access to information and functionality...
, for example by exposing custom controls for use with assistive technology
Assistive technology
Assistive technology or adaptive technology is an umbrella term that includes assistive, adaptive, and rehabilitative devices for people with disabilities and also includes the process used in selecting, locating, and using them...
and by filtering streams of new information by type and importance, became a second major focus for the project.
Support
Currently, support for IAccessible is in development for applications such as the Mozilla Application SuiteMozilla Application Suite
The Mozilla Application Suite is a cross-platform integrated Internet suite. Its development was initiated by Netscape Communications Corporation, before their acquisition by AOL. It is based on the source code of Netscape Communicator...
,
Opera Browser
Opera (web browser)
Opera is a web browser and Internet suite developed by Opera Software with over 200 million users worldwide. The browser handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, chatting on IRC, downloading files via BitTorrent,...
and NonVisual Desktop Access
NonVisual Desktop Access
NonVisual Desktop Access is a free, open source, portable screen reader for Microsoft Windows. The project was started by Michael Curran in 2006. The latest stable version is 2011.3NVDA is programmed in Python...
. Although IAccessible2 was introduced as a Windows accessibility API, Trolltech
Trolltech
Qt Development Frameworks is an Oslo, Norway-based software company best known for its Qt toolkit and application framework. Qt Development Frameworks is a wholly owned subsidiary of Nokia Corporation...
are treating IAccessible2 as a potential alternative to AT-SPI on Linux too, and planning to add preliminary support to Qt
Qt (toolkit)
Qt is a cross-platform application framework that is widely used for developing application software with a graphical user interface , and also used for developing non-GUI programs such as command-line tools and consoles for servers...
4.3.