On Thu, Jun 12, 2003 at 07:38:49PM -0800, Alan Kay wrote:
> Alan Borning did a Sketchpad influenced advance on constraint 
> programming in 1977 in Smalltalk-76. This code is around and several 
> people have come close to getting it going again in Squeak.
> 

ThingLab paper by Alan Borning is available here:
http://www.2share.com/thinglab/ThingLab%20-%20index.html

This seems to be a nice overview:
http://www.cosc.canterbury.ac.nz/~wolfgang/NewHome/cosc414/projects/thinglabFolder/html/thinglab.html

and Thinglab itself (this did work in the past to some extend (all the
Screenshots were done with it), would be interesting to have this on 
SqueakMap...): http://minnow.cc.gatech.edu/squeak/607

    Marcus

-- 
Marcus Denker marcus at ira.uka.de  -- Squeak! http://squeak.de