[laptop-accessibility] OLPC accessibility for Visually Impaired users

Peter Korn Peter.Korn at Sun.COM
Fri Nov 28 04:14:33 EST 2008


While screen readers are indeed a proven technology, adding them can be 
a surprisingly difficult task - especially depending upon the screen 
reading approached used.  All of the "screen scraping" screen readers 
(what I call "second generation screen readers") depend upon specific 
idiosyncrasies of how graphics rendering is done - and require that (for 
example) text rendering go through a single shared bottleneck in order 
to find out what that text is and track it in an Off-screen Model.  The 
third generation approach is built on top of a platform accessibility 
API or set of accessibility services (such as Orca on GNOME using AT-SPI 
or VoiceOver on Macintosh).  This requires that the platform in question 
make such an API/services and that the apps expose information via that 

The long term expectation for OLPC is that something like the Orca 
screen reader would work on top of AT-SPI.  Since Sugar makes use of 
many GNOME libraries, this is a natural assumption.  Unfortunately the 
inter-process communication mechanism for AT-SPI is CORBA, which is very 
heavy-weight and not easily stuffed into the small RAM envelope of 
OLPC.  This is being addressed by a project to migrate AT-SPI to DBUS, 
which is much lighter weight.  That process/project can be monitored at 
it's "web home" at 

Once that is done, it should be possible to bring Orca to the OLPC, at 
which point the task(s) will be focused around Sugar and the apps. 

Meanwhile, as Jim Gettys points out, it is also possible to stuff a 
general Linux + GNOME desktop (+ CORBA + Orca) onto an OLPC, though you 
may need to beef it up a bit with flash, etc.  And it'll be rather slow, 
and it looses some of what makes OLPC special and interesting at the 
software level (so in that case, perhaps what would be better is a 
netbook that will run Fedora or Ubuntu or OpenSolaris much better than 
you would get with any of those on OLPC hardware).

As to why this work I've described above hasn't already been completed, 
with resources dedicated to it by the OLPC project itself (vs. waiting 
for the open source community to get around to doing this at a somewhat 
slower pace), I'll have to leave that topic to Jim Gettys.  I would 
point out from my own experience at (smaller) commercial companies prior 
to coming to Sun and working on open source accessibility - you must 
always be sensitive to what your customers are telling you they want, 
even when you know about needs that those customers may not be asking 
about.  Software engineering is something of a zero-sum game: if you are 
putting effort in one area, it means that effort can't be going into 
some other area.  If you are adding features explicitly requested by 
customers, those same staff are probably not available to add features 
that customers aren't asking for.  And it is still a bit too rare of a 
thing for a customer to place accessibility high on their list of 
required features (something Section 508 in the U.S. has been incredibly 
helpful in doing for Federal sales in America).  I expect that with 
ratification of the U.N. Declaration on the Rights of Disabled Persons 
(see http://www.un.org/disabilities/countries.asp?navid=12&pid=166 for 
the list of signatory countries and 
http://www.un.org/disabilities/documents/maps/enablemap.jpg for a nice 
world-map showing signatory status), many more potential OLPC customers 
are going to start asking about accessibility, which will help enable 
engineers working on Sugar and OLPC generally to bump up the priority of 
accessibility work.


Peter Korn
Accessibility Architect & Principal Engineer,
Sun Microsystems, Inc.

> In reading more about accessibility and OLPC project, it seems to me 
> that designing accessibility features into the laptops wasn't a 
> priority. I would suggest that accessibility needs to be added to the 
> mission statement. Once this happens I feel that accessibility would 
> be give the proper attention an resources it deserves. 
> According to the OLPC wiki  
> <http://wiki.laptop.org/go/Our_software#Accessibility>http://wiki.laptop.org/go/Our_software#Accessibility, 
> " <http://wiki.laptop.org/go/Our_software#Accessibility>We've heard 
> that 10% of the world's population, or more than 600 million people, 
> live with life altering disabilities, and two thirds of those persons 
> are in developing countries (UN statistics)" 
> This would seem to justify incorporating accessibility into the 
> mission statement.
> Again, screen readers are a proven technology. It shouldn't be 
> difficult to add this functionality. There are more than enough blind 
> kids in the world to justify this.
> I don't mean to offend those working on accessibility for this 
> project. I think this is a great project but more attention should be 
> given to make the laptops more accessible.
> Thanks,
> David
> On Thu, Nov 27, 2008 at 11:41 AM, <tim.pennick at bt.com 
> <mailto:tim.pennick at bt.com>> wrote:
>     Hi All,
>     I have an OLPC machine on loan.  I'm blind, and am wondering about
>     the current state of play regarding facilities such as screen
>     readers which would allow me to access this machine.  Can anyone
>     tell me if there are features currently built into the OLPC
>     machines which will give me screen reader functionality, and if so
>     how to access them.  Alternatively, is it possible to load an
>     application such as Orca onto the oLPC machine and is there
>     documentation about how this works?
>     Regards,
>     Tim Pennick
>     Tim Pennick
>     Senior Researcher
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