+Great Green Room
+Forty and Eight
+Right Side Up
Jan Wolter died on January 1, 2015, from complications of influenza.
• His obituary is here
• His online guestbook is here
• His Facebook page is here
• There are paint-by-number puzzles in memory
of Jan that can be found by going to
and searching for
puzzles with the number 162 in the title.
• There is a bench in memory of Jan, located in Gallup Park
in Ann Arbor, in the sandbox next to the canoe livery. Mark Conger
organized a group of people who planned it and put it there. Jan's
next of kin are happy that the bench gets a lot of use.
You can reach Valerie Mates, Jan's life-partner, by using this form
to send a message.
I work as a freelance software developer.
Mostly I do Unix systems programming,
complex integrated web systems, and communications systems.
Look me up if you need some high-quality Unix software development done.
My partner at UnixMama.com
does similar work.
Web Paint by Number is an on-line
puzzle community where people create and solve a type of Japanese logic puzzle
known as nonograms, griddlers, or paint by number puzzles. It's been very
successful both as a sophisticated programming project and
as a vibrant on-line community.
Politaire is a a solitaire card game site
that allows you to modify game rules extensively. It's written entirely in
done on the server side.
The Great Green Room
is a blog / essay site
where I publish non-technical articles on any topic that captures my interest,
including global warming, gay marriage, Thomas the Tank Engine,
religion, hot water heaters, and physics.
The Pro-Both site
promotes an approach to the abortion issue that is both
pro-choice and pro-life and epitomizes my tendancy to argue
both sides of any issue.
Open Source Software
is an Apache module for using external programs to do authentication.
I am the current maintainer of this, and the author of
the related pwauth program
for doing web authentication out of Unix shadow password files,
as well as mod_authz_unixgroup,
a module for doing access control based on unix group membership.
Pbnsolve is a high performance
AI program for solving paint-by-number puzzles. It was originally designed to
validate puzzles for my webpbn site.
Backtalk is a sophisticated
open-source web-based computer conferencing system developed by
Steve Weiss and I.
Backtalk is used on several systems. It's spinoffs include
Booktalk, a conferencing system for schools and libraries, and
Fronttalk, a command-line interface cloning Picospan.
Orville Write is a much enhanced freeware
version of the Unix write as used on Grex and M-Net.
Party is the fine old Unix chat program
used on Grex and M-Net.
Gate is a text-gatherer, sort of a light-weight
text editor typically used with Picospan, Yapp or Fronttalk
Cursive is a program I wrote in 1987 to generate
ASCII text banners in a rough cursive font.
There is lots of discussion of browser incompatibilities in mouse and key
event handling, and a smattering of other topics.
Survey of Paint-by-Number Puzzle Solvers
examines a large number of AI tools designed to automatically
solve paint-by-number puzzles and compares their performance.
My Unix Incompatibility Notes
document some portability issues in commonly used C-language libraries under
A Guide to Web Authentication Alternatives
is a detailed technical discussion of different schemes for authenticating
users at web sites.
The Grex Staff Notes
describe several aspects of the Grex public-access computer system,
including a tour of the hardware,
discussions of security goals and privacy policies,
and technical descriptions on the kernel blocks and password database.
About the Author
Valerie and I have a three children,
Once upon a time I was a professor of Computer Science at Texas A&M
University, doing research in Robotics, Artificial Intelligence,
Computer-Aided Design and Computational Geometry.
I used to be an active participant in a number of virtual communities,
having served on the staff of
and served on the Grex board.
I also used to volunteer regularly for the
Ann Arbor Parks & Recreation Department's Natural Area Preservation group
doing mostly prescribed burns
and invasive species removal.
Seconds of Fame
I've given testimony against
Michigan's Internet censorship law
in Federal Court. (A
written draft of the testimony is available.)
I have an Erdös number of 3
(Erdös, [Alon | Aronov | Chung | Moran | Odlyzko | Pach | Pollack | Szemeredi | Yao],
[Bern | Guibas | Hershberger | Suri],
I've been quoted on Car Talk (though I didn't actually say the
"yada yada yada" part). I'm also
quoted in several on-line collections of
The first President Bush once signed a document honoring me for my cleverness.
Flixel is a simple "Lights Out" game that was
It acquired some features, but is still pretty simple.
Flood-It started life the same way and suffered
One of my early experiments with web technology back in 1995
was a sequence of pictures from my
which addressed the age old question
``Does travel really broaden you, or just narrow the world?''
In an (extended) moment of dementia and boredom, I compiled
Grover's Guide to Campus Phallic Symbols.
I promised never to do anything like that again, and have so far succeeded.
Grover's Guide to Auto Buying
laid down the law for SUVs, minivans and pickup trucks.
For those of us who tire of looking at web pages full of moving images,
busy backgrounds, and rambling text, I have developed a boldly new and
totally innovative web technology: blank web pages.
I can now offer blank web pages in
white for those absolutists amongst us,
and in eye-soothing shades of
You can reach Valerie Mates, Jan's life-partner, by using this form to send a message.