In the late 80s, Kent Beck and Ward Cunningham came up with HotDraw (http://c2.com/cgi/wiki?HotDraw), a two-dimensional graphics framework for structured drawing editors, originally written in Smalltalk-80. Since then, many implementations have been created, and the principles applied in a lot of places. While a lot has been learned, the original HotDraw still outshines many of its successors.
In the last few years, RoleModel Software was asked to build several systems with a complex underlying model where the user input was primarily direct graphical manipulation. This included:
* a system to support educational innovators at the Friday Institute, using direct manipulation tasks to test and teach various mathematical concepts to elementary age children.
* a deck designer for decks.com, to design and produce a 3D rendering, materials lists, and permit-ready plans to help do-it-yourselfers get professional designs in seconds.