Past Projects: Mercator

Past Projects: Mercator
Past Projects: Mercator
The Mercator System was designed to provide
transparent non-visual access to applications built using the X Window
System.  By “transparent” I mean that the applications in use do
not have to be rewritten to work with Mercator—any existing applications
should work with the system without modification.  To provide this
access to applications, there were two major problems that we had to overcome.
First, we needed a framework which would allow us to monitor, model, and
translate the graphical interfaces of X Windows applications without modifying
the applications.  Second, given these interface models, we needed
to devise a methodology for translating the original graphical interfaces
into non-visual ones—essentially mimicking the advantages of GUIs in a
non-visual presentation.
We wound up building several versions of
the system.  The first approaches used an X “pseudo-server” to monitor
the X protocol stream between clients and servers.  Based on our experiences
with these early efforts, we proposed a set of modifications to the standard
X platform.  Many of these modifications have been released by the
X Consortium as a part of the standard X distributions, starting in X11R6.
In 1995, the name of the system was changed
to
UltraSonix
(to prevent us from stepping on the toes of an existing
system called Mercator).  Development at Georgia Tech halted at the
end of 1995, as the primary developers moved on to new jobs.  In 1996,
a crew of intrepid hackers on the net got the source, and have been actively
engaged in porting the system to new platforms (particularly Linux), removing
dependencies on commercial software, and fixing bugs.
From day one, the project was a collaborative
effort involving a good number of people.  The folks that worked
on the system at Georgia Tech include:
David Burgess
Kevin Chen
Keith Edwards
John Goldthwaite
Stacy Ann Johnson
Beth Mynatt
Sue Liebeskind
Tom Rodriguez
Philip Seaver
John Selbie
Ian Smith
Kathryn Stockton
Our sponsors were Sun Microsystems, the
National Security Agency, and the NASA Marshall Space Flight Center.
While I was one of the principal developers
of the system, and managed its development for the last year or so at Georgia
Tech, I’m not involved in Mercator or accessibility work these days.   Thus, I
can’t support the software, and don’t have a lot of time to answer
questions about it.  The system is definitely “research-quality” software,
so be forewarned.  If you’re interested in using it, your best bet
is to hook up with the crew doing the port.  Their version of the
software has advanced far beyond the original Georgia Tech version anyway.
Mark Novak of the Trace Center is coordinating this development effort.
The home page for the porting and development effort is
here
Brian Sellden, one of the primary Linux hackers working with the code,
has a page with progress reports and other information
here
If you want the source code of the Georgia
Tech version it’s available
here
This software is free for non-commercial use, but if you want to use it
in a commercial product, bundle it with a commercial product, or make any
money off it, you need to talk to the Office of Technology Licensing at
Georgia Tech (call 404-894-9727 and ask for Kimberly Dunn).  The full
licensing text is:
The use of this program shall be restricted
to educational, non-commercial use only.  All inquiries regarding
licensing this software for commercial use may be addressed to:
Georgia Tech Research Corporation
Technology Licensing
Centennial ResearchBuilding - Rm. 275
400 Tenth Street, N.W.
Atlanta, Georgia
30332-0415
The software is Copyright 1995, Georgia
Tech Research Corporation, all rights reserved.
A pre-built binary for SPARCstations running
Solaris 2.5.x is available
here
It’s in Sun package format, so you can just use pkgadd to install it.
A warning:  configuring the thing for actual use is a bit tricky;
you probably shouldn’t just assume that you can use this code to get real
work done.
The old Georgia Tech web page on Mercator
was still around,
here
(last time I checked, anyway),
although it’s terribly out of date.
The list of papers about Mercator is rather
long.  Here’s the one’s I’ve been associated with:
“Mapping GUIs to Auditory
Interfaces,” Elizabeth D. Mynatt and W. Keith Edwards,
Proceedings of
the ACM Symposium on User Interface Software and Technology
(UIST),
pp. 61-70, Monterey, CA, 1992.
The paper above is the canonical (and most cited) paper on the conceptual
model behind Mercator, even though it describes a much earlier (and
obsolete) version of the system architecture.
“An Architecture for
Transforming Graphical Interfaces,” W. Keith Edwards and Elizabeth D. Mynatt,
Proceedings of the ACM Symposium on User Interface Software and Technology
(UIST), pp. 39-48, Marina del Rey, CA, November, 1994.
The paper above is a good source to cite for the architectural approach
of transforming graphical interfaces, as it is a reasonably accurate
overview of the way the system worked in its latest incarnation.
Metaphors for Nonvisual
Computing
(book chapter), Elizabeth D. Mynatt and W. Keith Edwards,
in
Extraordinary Human-Computer Interaction
, Alistair D. N. Edwards,
ed. Cambridge University Press, 1995.
“Access to Graphical
User Interfaces, Not Graphical Screens,” W. Keith Edwards and Elizabeth
D. Mynatt.
Interactions,
Volume 2.1, pp. 54-67, January, 1995.  (warning: the PDF file is a scan and is very large.)
“A Remote Access Protocol
for the X Window System,” W. Keith Edwards, Susan H. Liebeskind, Elizabeth
D. Mynatt, and William D. Walker.
The X Resource
, issue #13, Winter,
1995. O’Reilly Publishers, Sebastopol, CA.
“The Mercator Project:
A Nonvisual Interface to the X Window System,” W. Keith Edwards, Elizabeth
D. Mynatt, and Tom Rodriguez.
The X Resource
, issue #7, Summer,
1993. O’Reilly Publishers, Sebastopol, CA.
“Providing Access to
Graphical Interfaces, Not Graphical Screens,” W. Keith Edwards, Elizabeth
D. Mynatt, and Kathryn Stockton.
Proceedings of the ACM Conference on
Assistive and Enabling Technology
(ASSETS), pp. 47-54. Marina del Rey,
CA, November, 1994.
“Mapping GUIs to Auditory
Interfaces,” Elizabeth D. Mynatt and W. Keith Edwards,
Proceedings of
the ACM Symposium on User Interface Software and Technology
(UIST),
pp. 61-70, Monterey, CA, 1992.
“Runtime Translation
of X Interfaces to Support Visually-Impaired Users,” W. Keith Edwards and
Tom Rodriguez.
(For a more complete list of my papers,
go
here
.)