Whiteboard tools may be shared - that is, when one user draws, other viewers see the changes as they happen. More generally, almost any existing client-side application can be shared. Combined with invisible file transfer, shared applications turn MOO into a powerful, flexible data conferencing tool. We have demonstrated this functionality with the image analysis tool Skyview, the web browser NCSA Mosaic, and the mathematics package Mathematica, among others.
One obvious consequence is that geographically separated users may operate on the same data set simultaneously, or give tours or demonstrations to others. Indeed, a transcript of commands can be saved as a MOO object for later use (such as training employees, teaching students, or providing "active help" similar to the Macintosh's Apple Guides). One can easily imagine a number of possible uses:
Used in conjunction with the GUI toolkit, application sharing makes possible custom interfaces, such as the one we created for Skyview, pictured below. Features not normally present in Skyview but added to our interface included user-defined macros and buttons, command histories on a per-image basis, and shared access to image data. Images were displayed normally in Skyview, and user commands were re-broadcast to all users participating in a shared session.