As computers and large displays become cheaper, additional modes of human computer interaction are becoming possible. One can now set up an interactive workspace in which multiple computer displays and input devices are simultaneously visible and usable by one or more users. Unfortunately, the well-known event queue metaphor, which works well for a single user sitting in front of a single computer using a GUI, breaks down in such an interactive workspace. We propose the Event Heap as a novel mechanism by which multiple users, machines and applications can all simultaneously interact as consumers and generators of system events. The Event Heap is flexible, robust to failure of individual interactors, and sufficiently lightweight to be integrated easily with "legacy" single-user-GUI applications.
[PS Version (3.1 MB)]