Richard Schwerdtfeger <sch...@us.ibm.com>

Aaron Leventhal indicated that there were some questions about UI
Automation and its cohabitation with IAccessible2.

Currently, no major assistive technology vendor (ATV) supports UI
Automation (UIA). UIA is divided into a provider (application) and client
side (ATV) API. The client side portion runs in managed code (.NET, c#,
etc.). Today UIA requires ATVs to rewrite all or part of their software to
run a managed environment. This has prevented ATV adoption of UIA.
Microsoft claims to be writing an unmanaged client-side UIA implementation
piece which ATVs can support but that is post Vista ship. Given that this
has not been provided yet, and extremely few applications even support
UIA,, we believe UIA really needs much more testing with ATVs to prove that
is ready for wide scale adoption. Microsoft's challenge will be to get
large applications, like MS Office, and ATVs to support UIA and work out
any defects.

Now, all this said, the Vista desktop needed to be accessible so today
Vista access by screen readers is a combination of MSAA and screen
scraping. In short, access to the Vista desktop is like XP. Last year
Microsoft spent a significant effort adding the ability for screen readers
and magnifiers to capture information drawn to the desktop to reproduce
what is on XP. This capability is limited to the unmanaged environment.
Microsoft has done some mapping back to MSAA from managed code to support
basic MSAA and some text access but it is limited. Consequently, support
for unmanaged applications will depend on a client side unmanaged API
layer. Due to the limited number of managed applications there is little
business justification for ATVs to support them.

We do believe that more work will be required for application vendors to
switch from MSAA to UIA. With IAccessible2 we complement MSAA, as is, and
we have fully tested ATV support today. Also, the effort to enable
IAccessible2 enabled applications on other platforms is significantly
smaller. We have heavily tested and designed IAccessible2 to work on an
entire office suite and with input from the Mozilla foundation.
IAccessible2 is not new in that it is derived from APIs we helped designed
for UNIX and Java and which we have been working for some time.
IAccessible2 was designed with the help of ATVs like Freedom Scientific and
GW Micro during its implementation on IBM's new office suite. Please my
blog below for more information on the Missouri project.
We are also developing next generation tooling to support IAccessible2.

UIA has also not been designed to support ARIA and so changes to UIA may be
required to support it. Going forward IAccessible2 is an open standard and
will allow others in industry to enhance it as new technology warrants it.
Proprietary APIs are much more restrictive and this kind of participation
is very difficult. We believe they can both coexist on the same platform as
both are built on top of COM.

The significant value add of IAccessible2, for ATVs, is we do allow them to
continue to run in process to get the performance enhancements they have
realized with MSAA. This may prove difficult with the provider/client
architecture in UIA.

In short, we believe the two will coexist but because UIA has not been used
by major application vendors and ATVs we believe it will take some time to
be fully realized. In the meantime IAccessible2 will already have been
implemented to support large, rich, desktop applications and ARIA with full
ATV support. UIAs immediate value add will be for managed applications.

Beyond Mozilla's planned IAccessible2 support in Firefox 3 and our
implementation in our Notes 8 productivity editors which support ODF we
will be adding support in Eclipse. That work has just kicked off. By
implementing it in Eclipse any application built using Eclipse will be able
to make use of IAccessible2 and richer access. This will ultimately allow
us to do rich model-based authoring tools in our Rational product line, and
so on. Many vendor's products work on Eclipse,  ... IBM, SAP, etc.

There are other toolkit vendors and platform vendors planning to support
IAccessible2 and I hope they will be making those announcements in the near
future.

Rich

Rich Schwerdtfeger
Distinguished Engineer, SWG Accessibility Architect/Strategist
Chair, IBM Accessibility Architecture Review  Board
blog: http://www.ibm.com/developerworks/blogs/page/schwer