View article

This paper describes the software architecture for our pen-based electronic whiteboard system, called Flatland. The design goal of Flatland is to support various activities on personal office whiteboards, while maintaining the outstanding ease of use and informal appearance of conventional whiteboards. The GUI framework of existing window systems is too complicated and heavy-weight to achieve this goal, and so we designed a new architecture that works as a kind of window system for pen-based applications. Our architecture is characterized by its use of freeform strokes as the basic primitive for both input and output, flexible screen space segmentation, pluggable applications that can operate on each segment, and built-in history management mechanisms. This architecture is carefully designed to achieve simple, unified coding and high extensibility, which was essential to the iterative prototyping of the …