Unidraw [1] is a CeePlusPlus application framework for developing custom graphical editors.
JohnVlissides implemented on top of InterViews as part of his thesiswork at Stanford.  It has been mined by a number of application programmers over the years to build a variety of stuff [2], as well as being mined by JohnVlissides for several publications and articles on DesignPatterns.  
For a fairly in-depth description, see [3].

 [1] http://www.ivtools.org/ivtools/unidrawinfo.html
 [2] http://www.ivtools.org/ivtools/ivapps.html
 [3] http://www.amazon.com/exec/obidos/ASIN/0132139847/qid%3D929999695/002-8625093-9047430

For a more in-depth description, see "Unidraw: A Framework for Building Domain-Specific Graphical Editors," by JohnVlissides, ''ACM Transactions on Information Systems,'' 8(3):237-268 (1990).

For the ultimate description, see ''Generalized Graphical Object Editing,'' JohnVlissides' Ph.D. thesis, available as Stanford Computer Systems Lab Technical Report CSL-TR-90-427 (send e-mail to schulman@shasta.stanford.edu).

HotDraw is similar in intent but much smaller in scope.

The Berlin Project (http://www.berlin-consortium.org) is working on a Unidraw-like FactoryMethod object.

UnidrawFramework is closely related to the TooledComposite DesignPattern, also by JohnVlissides.

A writeup on the continued evolution of Unidraw as part of IvTools: http://www.ivtools.org/ivtools/reusingunidraw.txt
----
CategoryFramework